Ventilator-initiated prompt regarding detection of double triggering during ventilation

ABSTRACT

This disclosure describes systems and methods for monitoring and evaluating ventilatory parameters, analyzing those parameters and providing useful notifications and recommendations to clinicians. That is, modern ventilators monitor, evaluate, and graphically represent multiple ventilatory parameters. However, many clinicians may not easily recognize data patterns and correlations indicative of certain patient conditions, changes in patient condition, and/or effectiveness of ventilatory treatment. Further, clinicians may not readily determine appropriate ventilatory adjustments that may address certain patient conditions and/or the effectiveness of ventilatory treatment. Specifically, clinicians may not readily detect or recognize the presence of double triggering during ventilation. According to embodiments, a ventilator may be configured to monitor and evaluate diverse ventilatory parameters to detect double triggering and may issue notifications and recommendations suitable for a patient to the clinician when double triggering is implicated. The suitable notifications and recommendations may further be provided in a hierarchical format.

INTRODUCTION

A ventilator is a device that mechanically helps patients breathe byreplacing some or all of the muscular effort required to inflate anddeflate the lungs. In recent years, there has been an accelerated trendtowards an integrated clinical environment. That is, medical devices arebecoming increasingly integrated with communication, computing, andcontrol technologies. As a result, modern ventilatory equipment hasbecome increasingly complex, providing for detection and evaluation of amyriad of ventilatory parameters. However, due to the shear magnitude ofavailable ventilatory data, many clinicians may not readily assess andevaluate the diverse ventilatory data to detect certain patientconditions and/or changes in patient conditions, such as doubletriggering. Double triggering is a term that refers to a set ofinstances in which a ventilator delivers two breaths in response to whatis, in fact, a single patient effort. For example, hyperinflation,barotrauma, and/or asynchrony are dangerous conditions that may beimplicated/caused by double triggering.

Indeed, clinicians and patients may greatly benefit from ventilatornotifications when evaluation of various ventilatory data is indicativeof certain patient conditions, changes in patient conditions,effectiveness of ventilatory therapy, or otherwise.

VENTILATOR-INITIATED PROMPT REGARDING DETECTION OF DOUBLE TRIGGERINGDURING VENTILATION OF A PATIENT

This disclosure describes systems and methods for monitoring andevaluating ventilatory parameters, analyzing ventilatory data associatedwith those parameters, and providing useful notifications and/orrecommendations to clinicians. Modern ventilators monitor, evaluate, andgraphically represent, a myriad of ventilatory parameters. However, manyclinicians may not easily identify or recognize data patterns andcorrelations indicative of certain patient conditions, changes inpatient condition, and/or effectiveness of ventilatory treatment.Further, clinicians may not readily determine appropriate ventilatoryadjustments that may address certain patient conditions and/or theeffectiveness of ventilatory treatment. Specifically, clinicians may notreadily detect or recognize the presence of double triggering. Accordingto embodiments, a ventilator may be configured to monitor and evaluatediverse ventilatory parameters to detect double triggering and may issuenotifications and recommendations suitable for a patient to theclinician when double triggering is implicated. Double triggering is aterm that refers to a set of instances in which a ventilator deliverstwo breaths in response to what is, in fact, a single patient effort.The suitable notifications and recommendations may further be providedin a hierarchical format such that the clinician may selectively accesssummarized and/or detailed information regarding the presence of doubletriggering. In more automated systems, recommendations may beautomatically implemented.

According to embodiments, ventilator-implemented methods for detectingdouble triggering are provided. The methods include collecting dataassociated with ventilatory parameters and processing the collectedventilatory parameter data, wherein processing the collected ventilatoryparameter data includes deriving ventilatory parameter data from thecollected ventilatory parameter data. The methods also include analyzingthe processed ventilatory parameter data, which includes receiving oneor more predetermined thresholds associated with the processedventilatory parameter data and detecting whether the processedventilatory parameter data breaches the one or more predeterminedthresholds. The methods include determining that double triggering isimplicated upon detecting that the processed ventilatory data breachesthe one or more predetermined thresholds for more than a percentage ofthe patient-initiated mandatory breaths (e.g. 10% or 30%) within apredetermined amount of time or that the processed ventilatory databreaches the one or more predetermined thresholds for more than acertain number of breaths (e.g., 3 breaths) within a predeterminedamount of time. When double triggering is implicated, the methodsinclude issuing a smart prompt.

According to further embodiments, a ventilatory system for issuing asmart prompt when double triggering is implicated during ventilation ofa patient is provided. An appropriate notification message and anappropriate recommendation message may be determined and either or bothof the appropriate notification message and the appropriaterecommendation message may be displayed.

According to further embodiments, a graphical user interface fordisplaying one or more smart prompts corresponding to a detectedcondition is provided. The graphical user interface includes at leastone window and one or more elements within the at least one windowcomprising at least one smart prompt element for communicatinginformation regarding the detected condition, wherein the detectedcondition is double triggering.

These and various other features as well as advantages whichcharacterize the systems and methods described herein will be apparentfrom a reading of the following detailed description and a review of theassociated drawings. Additional features are set forth in thedescription which follows, and in part will be apparent from thedescription, or may he learned by practice of the technology. Thebenefits and features of the technology will be realized and attained bythe structure particularly pointed out in the written description andclaims hereof as well as the appended drawings.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The following drawing figures, which form a part of this application,are illustrative of described technology and are not meant to limit thescope of the claims in any manner, which scope shall be based on theclaims appended hereto.

FIG. 1 is a diagram illustrating an embodiment of an exemplaryventilator connected to a human patient.

FIG. 2 is a block-diagram illustrating an embodiment of a ventilatorysystem for monitoring and evaluating ventilatory parameters associatedwith double triggering.

FIG. 3 is a flow chart illustrating an embodiment of a method fordetecting an implication of double triggering.

FIG. 4 is a flow chart illustrating an embodiment of a method forissuing a smart prompt upon detecting an implication of doubletriggering.

FIG. 5 is an illustration of an embodiment of a graphical user interfacedisplaying a smart prompt having a notification message.

FIG. 6 is an illustration of an embodiment of a graphical user interfacedisplaying an expanded smart prompt having a notification message andone or more recommendation messages.

DETAILED DESCRIPTION

Although the techniques introduced above and discussed in detail belowmay be implemented for a variety of medical devices, the presentdisclosure will discuss the implementation of these techniques for usein a mechanical ventilator system. The reader will understand that thetechnology described in the context of a ventilator system could beadapted for use with other therapeutic equipment for alerting andadvising clinicians regarding deleted patient conditions.

This disclosure describes systems and methods for monitoring andevaluating ventilatory parameters, analyzing ventilatory data associatedwith those parameters, and providing useful notifications and/orrecommendations to clinicians. Modern ventilators monitor, evaluate, andgraphically represent a myriad of ventilatory parameters. However, manyclinicians may not easily identify or recognize data patterns andcorrelations indicative of certain patient conditions, changes inpatient condition, and/or effectiveness of ventilatory treatment.Further, clinicians may not readily determine appropriate ventilatoryadjustments that may address certain patient conditions and/or theeffectiveness of ventilatory treatment. Specifically, clinicians may notreadily detect or recognize the presence of double triggering duringventilation of a patient.

According to embodiments, a ventilator may be configured to monitor andevaluate diverse ventilatory parameters to detect double triggering andmay issue suitable notifications and recommendations to the clinicianwhen double triggering is implicated. The suitable notifications andrecommendations may further be provided in a hierarchical format suchthat the clinician may selectively access summarized and/or detailedinformation, regarding the presence of double triggering. In moreautomated systems, recommendations may he automatically implemented.

Ventilator System

FIG. 1 is a diagram illustrating an embodiment of an exemplaryventilator 100 connected to a human patient 150. Ventilator 100 includesa pneumatic system 102 (also referred to as a pressure generating system102) for circulating breathing gases to and from patient 150 via theventilation tubing system 130, which couples the patient 150 to thepneumatic system 102 via an invasive (e.g., endotracheal tube, as shown)or a non-invasive (e.g., nasal mask) patient interface 180.

Ventilation tubing system 130 (or patient circuit 130) may be a two-limb(shown) or a one-limb circuit for carrying gases to and from the patient150. In a two-limb embodiment, a fitting, typically referred to as a“wye-fitting” 170, may be provided to couple a patient interface 180 (asshown, an endotracheal tube) to an inspiratory limb 132 and anexpiratory limb 134 of the ventilation tubing system 130.

Pneumatic system 102 may be configured in a variety of ways. In thepresent example, pneumatic system 102 includes an expiratory module 108coupled with the expiratory limb 134 and an inspiratory module 104coupled with the inspiratory limb 132. Compressor 106 or other source(s)of pressurized gases (e.g., air, oxygen, and/or helium) is coupled withinspiratory module 104 to provide a gas source for ventilatory supportvia inspiratory limb 132.

The pneumatic system 102 may include a variety of other components,including mixing modules, valves, sensors, tubing, accumulators,filters, etc. Controller 110 is operaratively coupled with pneumaticsystem 102, signal measurement and acquisition systems, and an operatorinterlace 120 that may enable an operator to interact with theventilator 100 (e.g., change ventilator settings, select operationalmodes, breath types, view monitored parameters, etc). Controller 110 mayinclude memory 112, one or more processors 116, storage 114, and/orother components of the type commonly found in command and controlcomputing devices. In the depleted example, operator interlace 120includes a display 122 that may be touch-sensitive and/orvoice-activated, enabling the display 122 to serve both as an input andoutput device.

The memory 112 includes non-transitory, computer-readable storage mediathat stores software that is executed by the processor 116 and whichcontrols the operation of the ventilator 100. In an embodiment, thememory 112 includes one or more solid-state storage devices such asflash memory chips. In an alternative embodiment, the memory 112 may bemass storage connected to the processor 116 through a mass storagecontroller (not shown) and a communications bus (not shown). Althoughthe description of computer-readable media contained herein refers to asolid-state storage, it should be appreciated by those skilled in theart that computer-readable storage media can be any available media thatcan be accessed by the processor 116. That is, computer-readable storagemedia includes non-transitory, volatile and non-volatile, removable andnon-removable media implemented in any method or technology for storageof information such as computer-readable instructions, data structures,program modules or other data. For example, computer-readable storagemedia includes RAM, ROM, EPROM, EEPROM, flash memory or other solidstate memory technology, CD-ROM, DVD, or other optical storage, magneticcassettes, magnetic tape, magnetic disk storage or other magneticstorage devices, or any other medium which can be used to store thedesired information and which can be accessed by the computer.

Communication between components of the ventilatory system or betweenthe ventilatory system and other therapeutic-equipment and/or remotemonitoring systems may be conducted over a distributed network, asdescribed further herein, via wired or wireless means. Further, thepresent methods may be configured as a presentation layer built over theTCP/IP protocol. TCP/IP stands for “Transmission ControlProtocol/Internet Protocol” and provides a basic communication languagefor many local networks (such as intranets or extranets) and is theprimary communication language for the Internet. Specifically, TCP/IP isa bi-layer protocol that allow for the transmission of data over anetwork. The higher layer, or TCP layer, divides a message into smallerpackets, which are reassembled by a receiving TCP layer into theoriginal message. The lower layer, or IP layer, handles addressing androuting of packets so that they are properly received at a destination.

Ventilator Components

FIG. 2 is a block-diagram illustrating an embodiment of a ventilatorysystem 200 for monitoring and evaluating ventilatory parametersassociated with double triggering.

Ventilatory system 200 includes a ventilator 202 with its variousmodules and components. That is, ventilator 202 may further include,inter alia, memory 208, one or more processors 206, user interface 210,and ventilation module 212 (which may further include an inspirationmodule 214 and ventilation module 216). Memory 208 is defined asdescribed above for memory 112. Similarly, the one or more processors206 are defined as described above for one or more processors 116.Processors 206 may further be configured with a clock whereby elapsedtime may be monitored by the ventilatory system 200.

The ventilatory system 200 may also include a display module 204communicatively coupled to ventilator 202. Display module 204 providesvarious input screens, for receiving clinician input, and variousdisplay screens, for presenting useful information to the clinician. Thedisplay module 204 is configured to communicate with user interface 210and may include a graphical user interface (GUI). The GUI may be aninteractive display, e.g., a touch-sensitive screen or otherwise, andmay provide various windows and elements for receiving input andinterface command operations. Alternatively, other suitable means ofcommunication with the ventilator 202 may be provided, for instance by awheel, keyboard, mouse, or other suitable interactive device. Thus, userinterface 210 may accept commands and input through display module 204.Display module 204 may also provide useful information in the form ofvarious ventilatory data regarding the physical condition of a patientand/or a prescribed respiratory treatment. The useful information may bederived by the ventilator 202, based on data collected by a dataprocessing module 222, and the useful information may be displayed tothe clinician in the form of graphs, wave representations, pie graphs,or other suitable forms of graphic display. For example, one or moresmart prompts may be displayed on the GUI and/or display module 204 upondetection of an implication of double triggering by the ventilator.Additionally or alternatively, one or more smart prompts may becommunicated to a remote monitoring system, coupled via any suitablemeans to the ventilatory system 200.

Equation of Motion

Ventilation module 212 may oversee ventilation of a patient according toprescribed ventilatory settings. By way of general overview, the basicelements impacting ventilation may be described by the followingventilatory equation (also known as the Equation of Motion):

P _(m) +P _(v) =V _(T) /C+R*F

Here, P_(m) is a measure of muscular effort that is equivalent to thepressure generated by the muscles of a patient. If the patient's musclesare inactive, the P_(m) is equivalent to 0 cm H₂O. During inspiration,P_(v) represents the positive pressure delivered by a ventilator(generally in cm H₂O). V_(T) represents the tidal volume delivered, Crefers to the respiratory compliance, R represents the respiratoryresistance, and F represents the gas flow during inspiration (generallyin liters per min (L/m)). Alternatively, during exhalation, the Equationof Motion may be represented as:

P _(a) +P _(t) =V _(TE) /C+R*F

Here, P_(a) represents the positive pressure existing in the lungs(generally in cm H₂O), P_(t) represents the transairway pressure, V_(TE)represents the tidal volume exhaled, C refers to the respiratorycompliance, R represents the respiratory resistance, and F representsthe gas flow during exhalation (generally in liters per min (L/m)).

Pressure

For positive pressure ventilation, pressure at the upper airway opening(e.g., in the patient's mouth) is positive relative to the pressure atthe body's surface (i.e., relative to the ambient atmospheric pressureto which the patient's body surface is exposed, about 0 cm H₂O). Assuch, when P_(t) is zero, i.e., no ventilatory pressure is beingdelivered, the upper airway opening pressure will be equal to theambient pressure (i.e., about 0 cm H₂O). However, when ventilatorypressure is applied, a pressure gradient is created that allows gases toflow into the airway and ultimately into the lungs of a patient duringinspiration (or inhalation).

According to embodiments, additional pressure measurements may beobtained and evaluated. For example, transairway pressure, P_(t), whichrefers to the pressure differential or gradient between the upper airwayopening and the alveoli, may also be determined. P_(t) may berepresented mathematically as:

P _(t) =P _(awo) −P _(a)

Where P_(awo) refers to the pressure in the upper airway opening, ormouth, and P_(a) refers to the pressure within the alveolar space, orthe lungs (as described above). P_(t) may also be represented asfollows:

P _(t) =F*R

Where F refers to low and R refers to respiratory resistances, asdescribed below.

Additionally, lung pressure or alveolar pressure, P_(a) may be measuredor derived. For example, P_(a) may be measured via a distal pressuretransducer or other sensor near the lungs and/or the diaphragm.Alternatively, P_(a) may be estimated by measuring the plateau pressure,P_(Plat), via a proximal pressure transducer or other sensor at or nearthe airway opening. Plateau pressure, P_(Plat), refers to a slightplateau in pressure that is observed at the end of inspiration wheninspiration is held for a period of time, sometimes referred to as aninspiratory hold or pause maneuver, or a breath-hold maneuver. That is,when inspiration is held, pressure inside the alveoli and mouth areequal (i.e., no gas flow). However, as a result of muscular relaxationand elastance of the lungs during the hold period, forces are exerted onthe inflated lungs that create a positive pressure. This positivepressure is observed as a plateau in the pressure waveform that isslightly below the peak inspiratory pressure, P_(Peak), prior toinitiation of exhalation. As may be appreciated, for accuratemeasurement of P_(Plat), the patient should be sedated ornon-spontaneous (as muscular effort during the inspiratory pause mayskew the pressure measurement). Upon determining P_(Plat) based on thepressure waveform or otherwise, P_(Plat) may be used as an estimate ofP_(a) (alveolar pressure).

Flow and Volume

Volume refers to the amount of gas delivered to a patient's lungs,usually in liters (L). Flow refers to a rate of change in volume overtime (F=ΔV/ΔT). Flow is generally expressed in liters per minute (L/m orlpm) and, depending on whether gases are flowing into or out of thelungs, flow may be referred to as inspiratory flow or expiratory flow,respectively. According to embodiments, the ventilator may control therate of delivery of gases to the patient, i.e., inspiratory flow, andmay control the rate of release of gases from the patient, i.e.,expiratory flow.

As may be appreciated, volume and flow are closely related. That is,where flow is known or regulated, volume may be derived based on elapsedtime. Indeed, volume may be derived by integrating the flow waveform.According to embodiments, a tidal volume, V_(T), may be delivered uponreaching a set inspiratory time (T_(I)) at set inspiratory flow.Alternatively, set V_(T) and set inspiratory flow may determine theamount of time repaired for inspiration, i.e., T_(I).

Respiratory Compliance

Additional ventilatory parameters that may be measured and/or derivedmay include respiratory compliance and respiratory resistance, whichrefer to the load against which the patient and/or the ventilator mustwork to deliver gases to the lungs. Respiratory compliance may beinterchangeably referred to herein as compliance. Generally compliancerefers to a relative ease with which something distends and is theinverse of elastance, which refers to the tendency of something toreturn to its original form after being deformed. As related toventilation, compliance refers to the lung volume achieved for a givenamount of delivered pressure (C=ΔV/ΔP). Increased compliance may bedetected when the ventilator measures an increased volume relative tothe given amount of delivered pressure. Some lung diseases (e.g., acuterespiratory distress syndrome (ARDS)) may decrease compliance and, thus,require increased pressure to inflate the lungs. Alternatively, otherlung diseases may increase compliance, e.g., emphysema, and may requireless pressure to inflate the lungs.

Additionally or alternatively, static compliance and dynamic compliancemay be calculated. Static compliance, C_(S), represents complianceimpacted by elastic recoil at zero flow (e.g., of the chest wall,patient circuit, and alveoli). As elastic recoil of the chest wall andpatient circuit may remain relatively constant, static compliance maygenerally represent compliance as affected by elastic recoil of thealveoli. As described above, P_(Plat) refers to a slight plateau inpressure that is observed after relaxation of pleural muscles andelastic recoil, i.e., representing pressure delivered to overcomeelastic forces. As such, P_(Plat) provides a basis for estimating C_(S)as follows:

C _(S) =V _(T)/(P _(Plat) −EEP)

Where V_(T) refers to tidal volume, P_(Plat) refers to plateau pressure,and EEP refers to end-expiratory pressure, or baseline pressure(including PEEP and/or Auto-PEEP). Note that proper calculation of C_(S)depends on accurate measurement V_(T) and P_(Plat).

Dynamic compliance, C_(D) is measured during airflow and, as such, isimpacted by both elastic recoil and airway resistance. Peak inspiratorypressure, P_(Peak), which represents the highest pressure measuredduring inspiration, i.e., pressure delivered to overcome both elasticand resistive forces to inflate the lungs, is used to calculate C_(D) asfollows:

C _(D) =V _(T)/(P _(Peak) −EEP)

Where V_(T) refers to tidal volume, P_(Peak) refers to peak inspiratorypressure, and EEP refers to end-expiratory pressure. According toembodiments, ventilatory data may be more readily available for trendingcompliance of non-triggering patients than of triggering patients.

Respiratory Resistance

Respiratory resistance refers to frictional forces that resist airflow,e.g., due to synthetic structures (e.g., endotracheal tube, expiratoryvalve, etc.), anatomical structures (e.g., bronchial tree, esophagus,etc.), or viscous tissues of the lungs and adjacent organs. Respiratoryresistance may be interchangeably referred to herein as resistance.Resistance is highly dependant on the diameter of the airway. That is, alarger airway diameter entails less resistance and a higher concomitantflow. Alternatively, a smaller airway diameter entails higher resistanceand a lower concomitant flow. In fact, decreasing the diameter of theairway results in an exponential increase in resistance (e.g., two-timesreduction of diameter increases resistance by sixteen times). As may beappreciated, resistance may also increase due to a restriction of theairway that is the result of, inter alia, increased secretions,bronchial edema, mucous plugs, brochospasm, and/or kinking of thepatient interface (e.g., invasive endotracheal or tracheostomy tubes).

Airway resistance may further be represented mathematically as:

R=P _(t) /F

Where P_(t) refers to the transairway pressure and F refers to the flow.That is, P_(t) refers to the pressure necessary to overcome resistiveforces of the airway. Resistance may be expressed in centimeters ofwater per liter per second (i.e., cm H₂O/L/s).

Pulmonary Time Constant

As discussed above, compliance refers to the lung volume achieved for agiven amount of delivered pressure (C=ΔV/ΔP). That is, stateddifferently, volume delivered is equivalent to the compliance multipliedby the delivered pressure (ΔV=C*ΔP). However, as the lungs are notperfectly elastic, a period of time is needed to deliver the volume ΔVat pressure ΔP. A pulmonary time constant τ, may represent a timenecessary to inflate or exhale a given percentage of the volume atdelivered pressure ΔP. The pulmonary time constant, τ, may be calculatedby multiplying the respiratory resistance by the respiratory compliance(τ=R*C) for a given patient and τ is generally represented in seconds,s. The pulmonary time constant associated with exhalation of the givenpercentage of volume may be termed an expiratory time constant and thepulmonary time constant associated with inhalation of the givenpercentage of volume may be termed an inspiratory time constant.

According to some embodiments, when expiratory resistance data isavailable, the pulmonary time constant may be calculated by multiplyingexpiratory resistance by compliance. According to alternativeembodiments, the pulmonary time constant may be calculated based oninspiratory resistance and compliance. According to further embodiments,the expiratory time, T_(E), should be equal to or greater than three (3)pulmonary time constants to ensure adequate exhalation. That is, for atriggering patient, T_(E) (e.g., determined by trending T_(E) orotherwise) should be equal to or greater than 3 pulmonary timeconstants. For a non-triggering patient, set RR should yield a T_(E)that is equal to or greater than 3 pulmonary time constants.

Normal Resistance and Compliance

According to embodiments, normal respiratory resistance and compliancemay be determined based on a patient's predicted body weight (PBW) (orideal body weight (IBW)). That is, according to a standardized protocolor otherwise, patient data may be compiled such that normal respiratoryresistance and compliance values and/or ranges of values may bedetermined and provided to the ventilatory system 200. That is, amanufacturer, clinical facility, clinician, or otherwise, may configurethe ventilator with normal respiratory resistance and compliance valuesand/or ranges of values based on PBWs (or IBWs) of a patient population.Thereafter, during ventilation of a particular patient, respiratoryresistance and compliance data may be trended for the patient andcompared to normal values and/or ranges of values based on theparticular patient's PBW (or IBW). According to embodiments, theventilator may give an indication to the clinician regarding whether thetrended respiratory resistance and compliance data of the particularpatient falls into normal ranges. According to some embodiments, datamay be more readily available for trending resistance and compliance fornon-triggering patients than for triggering patients.

According to further embodiments, a predicted T_(E) may be determinedbased on a patient's PBW (or IBW). That is, according to a standardizedprotocol, or otherwise, patient population data may be compiled suchthat predicted T_(E) values and/or ranges of values may be determinedbased on PBWs (or IBWs) of the patient population and provided to theventilatory system 200. Actual (or trended) T_(E) for a particularpatient may then be compared to the predicted T_(E). As notedpreviously, increased resistance and/or compliance may result in anactual T_(E) that is longer than predicted T_(E). However, when actualT_(E) is consistent with predicted T_(E), this may indicate thatresistance and compliance for the particular patient fall into normalranges.

According to further embodiments, a normal pulmonary time constant, τ,may be determined based on a patient's PBW (or IBW). That is, accordingto a standardized protocol or otherwise, patient data may be compiledsuch that normal τ values and/or ranges of values may be determinedbased on PBWs (or IBWs) of a patient population and provided to theventilatory system 200. A calculated τ may be determined for aparticular patient by multiplying resistance by compliance (as describedabove, resistance and compliance data may be more readily available fora non-triggering patient). As the product of resistance and complianceresults in τ, increased resistance and/or compliance may result in anelevated τ value. However, when the calculated τ value for theparticular patient is consistent with the normal τ value, this mayindicate that the resistance and compliance of the particular patientfall into normal ranges.

Inspiration

Ventilation module 212 may further include an inspiration module 214configured to deliver gases to the patient according to prescribedventilatory settings. Specifically, inspiration module 214 maycorrespond to the inspiratory module 104 or may be otherwise coupled tosource(s) of pressurized gases (e.g., air, oxygen, and/or helium), andmay deliver gases to the patient. Inspiration module 214 may beconfigured to provide ventilation according to various ventilatorybreath types, e.g., via volume-targeted, pressure-targeted, or via anyother suitable breath types.

Volume ventilation, refers to various forms of volume-targetedventilation that regulate volume delivery to the patient. Differenttypes of volume ventilation are available depending on the specificimplementation of volume regulation, for example, for volume-cycledventilation, an end of inspiration is determined based on monitoring thevolume delivered to the patient. Volume ventilation may includevolume-control (VC), volume-targeted-pressure-control (VC+), orvolume-support (VS) breath types. Volume ventilation may be accomplishedby setting a target volume, or prescribed tidal volume, V_(T), fordelivery to the patient. According to embodiments, prescribed V_(T) andinspiratory time (T_(I)) may be set during ventilation start-up, basedon the patient's PBW (or IBW). In this case, flow will be dependent onthe prescribed V_(T) and set T_(I). Alternatively, prescribed V_(T) andflow may be set and T_(I) may result. According to some embodiments, apredicted T_(E) may be determined based on normal respiratory andcompliance values or value ranges based on the patient's PBW (or IBW),Additionally, a respiratory rate (RR) setting, generally in breaths/min,may be determined and configured. For a non-triggering patient, the setRR controls the timing for each inspiration. For a triggering patient,the RR setting applies if the patient stops triggering for some reasonand/or the patient's triggered RR drops below a threshold level.

According to embodiments, during volume ventilation, as volume and floware regulated by the ventilator, delivered V_(T), flow waveforms (orflow traces), and volume waveforms may be constant and may not beaffected by variations in lung or airway characteristics (e.g.,respiratory compliance and/or respiratory resistance). Alternatively,pressure readings may fluctuate based on lung or airway characteristics.According to some embodiments, the ventilator may control theinspiratory flow and then derive volume based on the inspiratory flowand elapsed time. For volume-cycled ventilation, when the derived volumeis equal to the prescribed V_(T), the ventilator may initiateexhalation.

According to alternative embodiments, the inspiration module 214 mayprovide ventilation via a form of pressure ventilation.Pressure-targeted breath types may he provided by regulating thepressure delivered to the patient in various ways. For example, duringpressure-cycled ventilation, an end of inspiration is determined basedon monitoring the pressure delivered to the patient. Pressureventilation may include a pressure-support (PS), a proportional assist(PA), or a pressure-control (PC) breath type, for example. Theproportional assist (PA) breath type provides pressure in proportion, tothe instantaneous patient effort during spontaneous ventilation and isbase on the equation of motion. Pressure ventilation may also includevarious forms of bi-level (BL) pressure ventilation, i.e., pressureventilation in which the inspiratory positive airway pressure (IPAP) ishigher than the expiratory positive airway pressure (EPAP).Specifically, pressure ventilation may be accomplished by setting atarget or prescribed pressure for delivery to the patient. Duringpressure ventilation, predicted T_(I) may be determined based on normalrespiratory and compliance values and on the patient's PBW (or IBW).According to some embodiments, a predicted T_(E) may be determined basedon normal respiratory and compliance values and based on the patient'sPBW (or IBW). A respiratory rate (RR) setting may also be determined andconfigured. For a non-triggering patient, the set RR controls the timingfor each inspiration. For a triggering patient, the RR setting appliesif the patient stops triggering for some reason and/or patienttriggering drops below a threshold RR level.

According to embodiments, during pressure ventilation, the ventilatormay maintain the same pressure waveform at the month, P_(awo),regardless of variations in lung or airway characteristics, e.g.,respiratory compliance and/or respiratory resistance. However, thevolume and flow waveforms may fluctuate based on lung and airwaycharacteristics. As noted above, pressure delivered to the upper airwaycreates a pressure gradient that enables gases to flow into a patient'slungs. The pressure from which a ventilator initiates inspiration istermed the end-expiratory pressure (EEP) or “baseline” pressure. Thispressure may be atmospheric pressure (about 0 cm H₂O), also referred tozero end-expiratory pressure (ZEEP). However, commonly, the baselinepressure may be positive, termed positive end-expiratory pressure(PEEP). Among other things, PEEP may promote higher oxygenationsaturation and/or may prevent alveolar collapse during exhalation. Underpressure-cycled ventilation, upon delivering the prescribed pressure theventilator may initiate exhalation.

According to still other embodiments, a combination of volume andpressure ventilation may be delivered to a patient, e.g.,volume-targeted-pressure-control (VC+) breath type. In particular, VC+may provide benefits of setting a target V_(T), while also allowing formonitoring variations in flow. As will be detailed further below,variations in flow may be indicative of various patient conditions.

Exhalation

Ventilation module 212 may further include an exhalation module 216configured to release gases from the patient's lungs according toprescribed ventilatory settings. Specifically, exhalation module 216 maycorrespond to expiratory module 108 or may otherwise be associated withand/or controlling an expiratory valve for releasing gases from thepatient. By way of general overview, a ventilator may initiateexhalation based on lapse of an inspiratory time setting (T_(I)) orother cycling criteria set by the clinician or derived from ventilatorsettings (e.g., detecting delivery of prescribed V_(T) or prescribedpressure based on a reference trajectory). Upon initiating theexpiratory phases exhalation module 216 may allow the patient to exhaleby opening an expiratory valve. As such, exhalation is passive, and thedirection of airflow, as described above, is governed by the pressuregradient between the patient's lungs (higher pressure) and the ambientsurface pressure (lower pressure). Although expiratory flow is passive,it may be regulated by the ventilator based on the size of theexpiratory valve opening.

Expiratory time (T_(E)) is the time from the end of inspiration untilthe patient triggers for a spontaneously breathing patient. For anon-triggering patient, it is the time from the end of inspiration untilthe next inspiration based on the set RR. In some cases, however, thetime required to return to the functional residual capacity (FRC) orresting capacity of the lungs is longer than provided by T_(E) (e.g.,because the patient triggers prior to fully exhaling or the set RR istoo high for a non-triggering patient). According to embodiments,various ventilatory settings may be adjusted to better match the time toreach FRC with the time available to reach FRC. For example, increasingflow will shorten T_(I), thereby increasing the amount of time availableto reach FRC. Alternatively, V_(T) may be decreased, resulting in lesstime required to reach FRC,

As may be further appreciated, at the point of transition betweeninspiration and exhalation, the direction of airflow may abruptly changefrom flowing into the lungs to flowing out of the lungs or vice versadepending on the transition. Stated another way, inspiratory flow may bemeasurable in the ventilatory circuit until P_(Peak) is reached, atwhich point flow is zero. thereafter, upon initiation of exhalation,expiratory flow is measurable in the ventilatory circuit until thepressure gradient between the lungs and the body's surface reaches zero(again, resulting in zero flow). However, in some cases, as will bedescribed further herein, expiratory flow may still be positive, i.e.,measurable, at the end of exhalation (termed positive end-expiratoryflow or positive EEF). In this case, positive EEF is an indication thatthe pressure gradient has not reached zero or, similarly, that thepatient has not completely exhaled. Although a single occurrence ofpremature inspiration may not warrant concern, repeated detection ofpositive EEF may be indicative of Auto-PEEP.

Ventilator Synchrony and Patient Triggering

According to some embodiments, the inspiration module 214 and/or theexhalation module 216 may be configured to synchronize ventilation witha spontaneously-breathing, or triggering, patient. That is, theventilator may be configured to detect patient effort and may initiate atransition from exhalation to inspiration (or from inspiration toexhalation) in response. Triggering refers to the transition fromexhalation to inspiration in order to distinguish it from the transitionfrom inspiration to exhalation (referred to as cycling). Ventilationsystems, depending on their breath type, may trigger and/or cycleautomatically, or in response to a detection of patient effort, or both.

Specifically, the ventilator may detect patient effort via apressure-monitoring method, a flow-monitoring method, direct or indirectmeasurement of nerve impulses, or any other suitable method. Sensingdevices may be either internal or distributed and may include anysuitable sensing device, as described further herein. In addition, thesensitivity of the ventilator to changes in pressure and/or flow may beadjusted such that the ventilator may properly detect the patienteffort, i.e., the lower the pressure or flow change setting the moresensitive the ventilator may be to patient triggering.

According to embodiments, a pressure-triggering method may involve theventilator monitoring the circuit pressure, as described above, anddetecting a slight drop in circuit pressure. The slight drop in circuitpressure may indicate that the patient's respiratory muscles, P_(m), arecreating a slight negative pressure gradient between the patient's lungsand the airway opening in an effort to inspire. The ventilator mayinterpret the slight drop in circuit pressure as patient effort and mayconsequently initiate inspiration by delivering respiratory gases.

Alternatively, the ventilator may detect a flow-triggered event.Specifically, the ventilator may monitor the circuit flow, as describedabove. If the ventilator detects a slight drop in flow duringexhalation, this may indicate, again, that the patient is attempting toinspire. In this case, the ventilator is detecting a drop in bias flow(or baseline flow) attributable to a slight redirection of gases intothe patient's lungs (in response to a slightly negative pressuregradient as discussed above). Bias flow refers to a constant flowexisting in the circuit during exhalation that enables the ventilator todetect expiratory flow changes and patient triggering. For example,while gases are generally flowing out of the patient's lungs duringexhalation, a drop in flow may occur as some gas is redirected and flowsinto the lungs in response to the slightly negative pressure gradientbetween the patient's lungs and the body's surface. Thus, when theventilator detects a slight drop in flow below the bias flow by apredetermined threshold amount (e.g., 2 L/min below bias flow), it mayinterpret the drop as a patient trigger and may consequently initiateinspiration by delivering respiratory gases.

Volume-Control Breath Type

In some embodiments, ventilation module 212 may further include aninspiration module 214 configured to deliver gases to the patientaccording to volume-control (VC). The VC breath type allows a clinicianto set a respiratory rate and to select a volume to be administered to apatient during a mandatory breath. When using VC, a clinician sets adesired tidal volume, flow wave form shape, and an inspiratory flow rateor inspiratory time. These variables determine how much volume of gas isdelivered to the patient and the duration of inspiration during eachmandatory breath inspiratory phase. The mandatory breaths areadministered according to the set respiratory rate.

For VC, when the delivered volume is equal to the prescribed tidalvolume, the ventilator may initiate exhalation. Exhalation lasts fromthe time at which prescribed volume is reached until the start of thenext ventilator mandated inspiration. This expiration time is determinedby the respiratory rate set by the clinician and any participation abovethe set rate by the patient. Upon the end of exhalation, another VCmandatory breath is given to the patient.

During VC, delivered volume and flow waveforms may remain constant andmay not be affected by variations in lung or airway characteristics.Alternatively, pressure readings may fluctuate based on lung or airwaycharacteristics. According to some embodiments, the ventilator maycontrol the inspiratory flow and then derive volume based on theinspiratory flow and elapsed time.

In some embodiments, VC may also be delivered to a triggering patient.When VC is delivered to a triggering patient, the breath period (i.e.time between breaths) is a function of the frequency at which thepatient is triggering breaths. That is, the ventilator will trigger theinhalation based upon the respiratory rate setting or the patienteffort. If no patient effort is detected, the ventilator will deliveranother mandatory breath at the predetermined respiratory rate.

Volume-Targeted-Pressure-Control Breath Type

In further embodiments, ventilation module 212 may further include aninspiration module 214 configured to deliver gases to the patient usinga volume-targeted-pressure-control (VC+) breath type. The VC+ breathtype is a combination of volume and pressure control breath types thatmay be delivered to a patient as a mandatory breath. In particular, VC+may provide the benefits associated with setting a target tidal volume,while also allowing for variable flow. Variable flow may he helpful inmeeting inspiratory flow demands for actively breathing patients.

As may be appreciated, when resistance increases it becomes moredifficult to pass gases into and out of the lungs, decreasing flow. Forexample, when a patient is intubated, i.e., having either anendotracheal or a tracheostomy tube in place, resistance may beincreased as a result of the smaller diameter of the tube over apatient's natural airway. In addition, increased resistance may beobserved in patients with obstructive disorders, such as COPD, asthma,etc. Higher resistance may necessitate, inter alia, a higher inspiratorytime setting for delivering a prescribed pressure or volume of gases, alower respiratory rate resulting in a higher expiratory time forcomplete exhalation of gases.

Unlike VC, when the set inspiratory time is reached, the ventilator mayinitiate expiration. Expiration lasts from the end of inspiration untilthe beginning of the next inspiration. For a non-triggering patient, theexpiratory time (T_(E)) is based on the respiratory rate set by theclinician. Upon the end of expiration, another VC+ mandatory breath isgiven to the patient.

By controlling target tidal volume and allowing for variable flow, VC+allows a clinician to maintain the volume while allowing the flow andpressure targets to fluctuate.

Volume-Support Breath Type

In some embodiments, ventilation module 212 may further include aninspiration module 214 configured to deliver gases to the patientaccording to volume-support (VS) breath type. The VS breath type isutilized in the present disclosure as a spontaneous breath. VS isgenerally used with a triggering (spontaneously breathing) patient whenthe patient is ready to be weaned from a ventilator or when the patientcannot do all of the work of breathing on his or her own. When theventilator senses patient inspiratory effort, the ventilator delivers aset tidal volume during inspiration. The tidal volume may be set andadjusted by the clinician. The patient controls the rate, inspiratoryflow, and has some control over the inspiratory time. The ventilatorthen adjusts the pressure over several breaths to achieve the set tidalvolume. When the machine senses a decrease in flow, or inspiration timereaches a predetermined limit, the ventilator determines thatinspiration is ending. When delivered as a spontaneous breath,expiration in VS lasts from a determination that inspiration is endinguntil the ventilator senses a next patient effort to breath.

Pressure-Control Breath Type

In additional embodiments, ventilation module 212 may further include aninspiration module 214 configured to deliver gases to the patientaccording to the pressure-control (PC) breath type. PC allows aclinician to select a pressure to be administered to a patient during amandatory breath. When using the PC breath type, a clinician sets adesired pressure, inspiratory time, and respiratory rate for a patient.These variables determine the pressure of the gas delivered to thepatient during each mandatory breath inspiration. The mandatory breathsare administered according to the set respiratory rate.

For the PC breath type, when the inspiratory time is equal to theprescribed inspiratory time, the ventilator may initiate expiration.Expiration lasts from the end of inspiration until the next inspiration.Upon the end of expiration, another PC mandatory breath is given to thepatient.

During PC breaths, the ventilator may maintain the same pressurewaveform at the mouth, regardless of variations in lung or airwaycharacteristics, e.g., respiratory compliance and/or respiratoryresistance. However, the volume and low waveforms may fluctuate based onlung and airway characteristics.

In some embodiments, PC may also be delivered for triggering patients.When PC is delivered with triggering, the breath period (i.e., timebetween breaths) is a function of the respiratory rate of the patient.The ventilator will trigger the inhalation based upon the respiratoryrate setting or the patient's trigger effort, but cycling to exhalationwill be based upon elapsed inspiratory time. The inspiratory time is setby the clinician. The inspiratory flow is delivered based upon thepressure setting and patient physiology. Should the patient create airexpiratory effort in the middle of the mandatory inspiratory phase, theventilator will respond by reducing flow. If no patient effort isdetected, the ventilator will deliver another mandatory breath at thepredetermined respiratory rate.

PC with triggering overcomes some of the problems encountered by othermandatory breath types that use artificially set inspiratory flow rates.For example, if the inspiratory flow is artificially set lower than apatient's demand, the patient will feel starved for flow. This can leadto undesirable effects, including increased work of breathing. Inaddition, should the patient begin to exhale when using one of thetraditional mandatory breath types, the patient's expiratory effort isignored since the inspiratory flow is mandated by the ventilatorsettings.

Pressure-Support Breath Type

In further embodiments, ventilation module 212 may further include aninspiration module 214 configured to deliver gases to the patientaccording to a pressure-support (PS) breath type. PS is a form ofassisted ventilation and is utilized in the present disclosure during aspontaneous breath. PS is a patient triggered breath and is typicallyused when a patient is ready to be weaned from a ventilator or for whenpatients are breathing spontaneously but cannot do all the work ofbreathing on their own. When the ventilator senses patient inspiratoryeffort, the ventilator provides a constant pressure during inspiration.The pressure may be set and adjusted by the clinician. The patientcontrols the rate, inspiratory flow, and to an extent, the inspiratorytime. The ventilator delivers the set pressure and allows the flow tovary. When the machine senses a decrease in flow, or determines thatinspiratory time has reached a predetermined limit, the ventilatordetermines that inspiration is ending. When delivered as a spontaneousbreath, expiration in PS lasts from a determination that inspiration isending until the ventilator senses a patient effort to breath.

Expiratory Sensitivity

As discussed above, ventilation module 212 may oversee ventilation of apatient according to prescribed ventilatory settings. In one embodiment,the expiratory sensitivity (E_(SENS)) is set by a clinician or operator.According to embodiments, E_(SENS) sets the percentage of delivered peakinspiratory flow necessary to terminate inspiration and initiateexhalation. In some embodiments, the clinician operator determines theE_(SENS) setting, which is adjustable from 1% to 80%. A lower setE_(SENS) increases inspiration time and a higher set E_(SENS) decreasesinspiration time. The E_(SENS) setting may be utilized to limitunnecessary expiratory work and to improve patient-ventilator synchrony.

The ventilatory system 200 may also include one or mote distributedsensors 218 communicatively coupled to ventilator 202. Distributedsensors 218 may communicate with various components of ventilator 202,e.g., ventilation module 212, internal sensors 220, data processingmodule 222, double triggering detection module 224, and any othersuitable components and/or modules. Distributed sensors 218 may detectchanges in ventilatory parameters indicative of double triggering, forexample. Distributed sensors 218 may be placed in any suitable location,e.g., within the ventilatory circuitry or other devices communicativelycoupled to the ventilator. For example, sensors may be affixed to theventilatory tubing or may be imbedded in the tubing itself. According tosome embodiments, sensors may be provided at or near the lungs (ordiaphragm) for detecting a pressure in the lungs. Additionally oralternatively, sensors may be affixed or imbedded in or near wye-fitting170 and/or patient interface 180, as described above.

Distributed sensors 218 may further include pressure transducers thatmay detect changes in circuit pressure (e.g., electromechanicaltransducers including piezoelectric, variable capacitance, or straingauge). Distributed sensors 218 may further include various flowmetersfor detecting airflow (e.g., differential pressure pneumotachometers).For example, some flowmeters may use obstructions to create a pressuredecrease corresponding to the flow across the device (e.g., differentialpressure pneumotachometers) and other flowmeters may use turbines suchthat flow may be determined based on the rate of turbine rotation (e.g.,turbine flowmeters). Alternatively, sensors may utilize optical orultrasound techniques for measuring changes in ventilatory parameters. Apatient's blood parameters or concentrations of expired gases may alsobe monitored by sensors to detect physiological changes that may be usedas indicators to study physiological effects of ventilation, wherein theresults of such studies may be used for diagnostic or therapeuticpurposes. Indeed, any distributed sensory device useful for monitoringchanges in measurable parameters daring ventilatory treatment may beemployed in accordance with embodiments described herein.

Ventilator 202 may farther include one or more internal sensors 220.Similar to distributed sensors 218, internal sensors 220 may communicatewith various components of ventilator 202, e.g., ventilation module 212,internal sensors 220, data processing module 222, double triggeringdetection module 224, and any other suitable components and/or modules.Internal sensors 220 may employ any suitable sensory or derivativetechnique for monitoring one or more parameters associated with theventilation of a patient. However, the one or more internal sensors 220may be placed in any suitable internal location, such as, within theventilatory circuitry or within components or modules of ventilator 202.For example, sensors may be coupled to the inspiratory and/or expiratorymodules for detecting changes in, for example, circuit pressure and/orflow. Specifically, internal sensors 220 may include pressuretransducers and flowmeters for measuring changes in circuit pressure andairflow. Additionally or alternatively, internal sensors 220 may utilizeoptical or ultrasound techniques for measuring changes in ventilatoryparameters. For example, a patient's expired gases may be monitored byinternal sensors 220 to detect physiological changes indicative of thepatient's condition and/or treatment, for example. Indeed, internalsensors 220 may employ any suitable mechanism for monitoring parametersof interest in accordance with embodiments described herein.

As should be appreciated, with reference to the Equation of Motion,ventilatory parameters are highly interrelated and, according toembodiments, may be either directly or indirectly monitored. That is,parameters may be directly monitored by one or more sensors, asdescribed above, or may be indirectly monitored by derivation accordingto the Equation of Motion.

Ventilatory Data

Ventilator 202 may further include a data processing module 222. Asnoted above, distributed sensors 218 and internal sensors 220 maycollect data regarding various ventilatory parameters. A ventilatoryparameter refers to any factor, characteristic, or measurementassociated with the ventilation of a patient, whether monitored by theventilator or by any other device. Sensors may further transmitcollected data to the data processing module 222 and, according toembodiments, the data processing module 222 may be configured to collectdata regarding some ventilatory parameters, to derive data regardingother ventilatory parameters, and to graphically represent collected andderived data to the clinician and/or other modules of the ventilatorysystem 200. Some collected, derived, and/or graphically represented datamay be indicative of double triggering. For example, data regardingexpiratory time, exhaled tidal volume, inspiratory time setting (T_(I)),etc., may be collected, derived, and/or graphically represented by dataprocessing module 222.

Flow Data

For example, according to embodiments, data processing module 222 may beconfigured to monitor inspiratory and expiratory flow. Flow may bemeasured by any appropriate, internal or distributed device or sensorwithin the ventilatory system 200. As described above, flowmeters may beemployed by the ventilatory system 200 to detect circuit flow. However,any suitable device either known or developed in the future may be usedfor detecting airflow in the ventilatory circuit.

Data processing module 222 may be further configured to plot monitoredflow data graphically via any suitable means. For example, according toembodiments, flow data may be plotted versus time (flow waveform),versus volume (flow-volume loop), or versus any other suitable parameteras may be useful to a clinician. According to embodiments, flow may beplotted such that each breath may be independently identified. Further,flow may be plotted such that inspiratory flow and expiratory flow maybe independently identified, e.g., inspiratory flow may be representedin one color and expiratory flow may be represented in another color.According to additional embodiments, flow waveforms and flow-volumeloops, for example, may be represented alongside additional graphicalrepresentations, e.g., representations of volume, pressure, etc., suchthat clinicians may substantially simultaneously visualize a variety ofventilatory parameters associated with each breath.

As may be appreciated, flow decreases as resistance increases, making itmore difficult to pass gases into and out of the lungs (i.e.,F=P_(t)/R). For example, when a patient is intubated, i.e., havingeither an endotracheal or a tracheostomy tube in place, resistance maybe increased as a result of the smaller diameter of the tube over apatient's natural airway. In addition, increased resistance may beobserved in patients with obstructive disorders, such as COPD, asthma,etc. Higher resistance may necessitate, inter alia, a higher inspiratorytime setting (T_(I)) for delivering a prescribed pressure or volume ofgases, a higher flow setting for delivering prescribed pressure orvolume, a lower respiratory rate resulting in a higher expiratory time(T_(E)) for complete exhalation of gases, etc.

Specifically, changes in flow may be detected by evaluating various flowdata. For example, by evaluating FV loops, as described above, anincrease in resistance may be detected over a number of breaths. Thatis, upon comparing consecutive FV loops, the expiratory plot for each FVloop may reflect a progressive reduction in expiratory flow (i.e., asmaller FV loop), indicative of increasing resistance.

Pressure Data

According to embodiments, data processing module 222 may be configuredto monitor pressure. Pressure may be measured by any appropriate,internal or distributed device or sensor within the ventilatory system200. For example, pressure may be monitored by proximalelectromechanical transducers connected near the airway opening (e.g.,on the inspiratory limb, expiratory limb, attire patient interface,etc.). Alternatively, pressure may be monitored distally, at or near thelungs and/or diaphragm of the patient.

For example, P_(Peak) and/or P_(Plat) (estimating P_(a)) may be measuredproximally (e.g., at or near the airway opening) via single-pointpressure measurements. According to embodiments, P_(Plat) (estimatingP_(a)) may be measured during an inspiratory pause maneuver (e.g.,expiratory and inspiratory valves are closed briefly at the end ofinspiration for measuring the P_(Plat) at zero flow). According to otherembodiments, circuit pressure may be measured during an expiratory pausemaneuver (e.g., expiratory and inspiratory valves are closed briefly atthe end of exhalation for measuring EEP at zero flow).

Data processing module 222 may be further configured to plot monitoredpressure data graphically via any suitable means. For example, accordingto embodiments, pressure data may be plotted versus time (pressurewaveform), versus volume (pressure-volume loop or PV loop), or versusany other suitable parameter as may be useful to a clinician. Accordingto embodiments, pressure may be plotted such that each breath may beindependently identified. Further, pressure may be plotted such thatinspiratory pressure and expiratory pressure may be independentlyidentified, e.g., inspiratory pressure may be represented in one colorand expiratory pressure may be represented in another color. Accordingto additional embodiment, pressure waveforms and PV loops, for example,may be represented alongside additional graphical representations, e.g.,representations of volume, flow, etc., such that a clinician maysubstantially simultaneously visualize a variety of parametersassociated with each breath.

According to embodiment, PV loops may provide useful clinical anddiagnostic information to clinicians regarding the respiratoryresistance or compliance of a patient. Specifically, upon comparing PVloops from successive breaths, an increase in resistance may be detectedwhen successive PV loops shorten and widen over time. That is, atconstant pressure, less volume is delivered to the lungs when resistanceis increasing, resulting in a shorter, wider PV loop. According toalternative embodiments, a PV loop may provide a visual representation,in the area between the inspiratory plot of pressure vs. volume and theexpiratory plot of pressure vs. volume, which is indicative ofrespiratory compliance. Further, PV loops may be compared to one anotherto determine whether compliance has changed. Additionally oralternatively, optimal compliance may be determined. That is, optimalcompliance may correspond to the dynamic compliance determined from a PVloop during a recruitment maneuver, for example.

According to additional embodiment, PV curves may be used to compareC_(S) and C_(D) over a number of breaths. For example, a first PV curvemay be plotted for C_(S) (based on P_(Plot) less EEP) and a second PVcurve may be plotted C_(D) (based on P_(Peak) less EEP). Under normalconditions, C_(S) and C_(D) curves may be very similar, with the C_(D)curve mimicking the C_(S) curve but shifted to the right (i.e., plottedat higher pressure). However, in some cases the C_(D) curve may flattenout and shift to the right relative to the C_(S) curve. This graphicalrepresentation may illustrate increasing P_(t), and thus increasing R,which may be due to mucous plugging or bronchospasm, for example. Inother cases, both the C_(D) curve and C_(S) curves may flatten out andshift to the right. This graphical representation may illustrate anincrease in P_(Peak) and P_(Plat), without an increase in P_(t), andthus may implicate a decrease in lung compliance, which may be due totension pneumothorax, atelectasis, pulmonary edema, pneumonia, bronchialintubation, etc.

As may be further appreciated, relationships between resistance, staticcompliance, dynamic compliance, and various pressure readings may giveindications of patient condition. For example, when C_(S) increases,C_(D) increases and, similarly, when R increases, C_(D) increases.Additionally, as discussed previously, P_(t) represents the differencein pressure attributable to resistive forces over elastic forces. Thus,where P_(Peak) and P_(t) are increasing with constant V_(T) delivery, Ris increasing (i.e., where P_(Peak) is increasing without a concomitantincrease in P_(Plat)). Where P_(t) is roughly constant, but whereP_(Peak) and P_(Plat) and are increasing with a constant V_(T) delivery,C_(S) is increasing.

Volume Data

According to embodiments, data processing module 222 may be configuredto derive volume via any suitable means. For example, as describedabove, during volume ventilation, a prescribed V_(T) may be set fordelivery to the patient. The actual volume delivered may be derived bymonitoring the inspiratory flow over time (i.e., V=F*T). Stateddifferently, integration of flow over time will yield volume. Accordingto embodiments, V_(T) is completely delivered upon reaching T_(I).Similarly, the expiratory flow may be monitored such that expired tidalvolume (V_(TE)) may be derived. That is, under ordinary conditions, uponreaching the T_(E), the prescribed V_(T) delivered should be completelyexhaled and FRC should be reached. However, under some conditions T_(E)is inadequate for complete exhalation and FRC is not reached.

Data processing module 222 may be further configured to plot derivedvolume data graphically via any suitable means. For example, accordingto embodiments, volume data may be plotted versus time (volumewaveform), versus flow (flow-volume loop or FV loop), or versus anyother suitable parameter as may be useful to a clinician. According toembodiments, volume may be plotted such that each breath may beindependently identified. Further, volume may be plotted such thatprescribed V_(T) and V_(TE) may be independently identified, e.g.,prescribed V_(T) may be represented in one color and V_(TE) may berepresented in another color. According to additional embodiments,volume waveforms and FV loops, for example, may be represented alongsideadditional graphical representations, e.g., representations of pressure,flow, etc., such that a clinician may substantially simultaneouslyvisualize a variety of parameters associated with each breath.

According to embodiments, data processing module 233 may be configuredto determine if the ventilation tubing system 130 or patient circuit hasbecome disconnected from the patient or the ventilator duringventilation. Data processing module 222 determines that a patientcircuit is disconnected by any suitable means. In some embodiments, dataprocessing module 222 determines that the patient circuit isdisconnected by evaluating data, such as exhaled pressure and/or exhaledvolume. In further embodiments, data processing module 222 determines ifthe patient circuit is disconnected by determining if a disconnect alarmhas been executed. If the disconnect alarm has been executed, then dataprocessing module 222 determines that the patient circuit isdisconnected. If the disconnect alarm has not been executed, then dataprocessing module 222 determines that the patient circuit is connected.

Breath Type

According to embodiments, data processing module 232 may be configuredto identify the ventilator breath type. Data processing module 222determines the breath type by any suitable means or methods. In someembodiments, data processing module 222 determines the breath type basedon clinician or operator input and/or selection. In further embodiments,data processing module 222 determines the breath type based onventilator selection of the breath type. For example, some breath, typesinclude VC, PC, VC+, PS, PA, and VS.

Double Trigger Detection

Ventilator 202 may further include a double triggering detection module224. Double triggering is a term that refers to a set of instances inwhich a ventilator delivers two breaths in response to what is, in fact,a single patient effort. A double trigger occurs when the ventilatordelivers two or more ventilator cycles separated by a very shortexpiratory time, with at least one breath being triggered by thepatient. Typically the first cycle is patient triggered and the secondbreath is triggered by either a continuation of the patient'sinspiratory effort or from some anomalous condition that is interpretedby the ventilator as a second patient effort. Because of the shortexpiratory time, the additional breaths may come before the patient hasthe chance to fully exhale and may cause gas-trapping in the lungs.Accordingly, double triggering can lead to patient discomfort and/or anincrease in the length of ventilation time. Further, double triggeringcan lead to hyper inflation, barotraumas, hypoxia, and/or asynchrony.

Barotrauma may result from the over-distension of alveoli, which maycause disruption of the alveolar epithelium. Further as pressure in thealveoli increases, some alveoli may rupture, allowing gases to seep intothe perivascular sheath and into the mediastinum. This condition may bereferred to as pulmonary interstitial emphysema (PIE). Furthercomplications associated with PIE may result in Pneumothorax (i.e.,partial to complete collapse of a lung due to gases collected in thepleural cavity).

Double triggering may result when there is a mismatch between theventilation setting for inspiratory time and the patient's neurologicalinspiratory time. The patient's neurological inspiratory time is theamount of time desired by the patient between breaths. The patientneurological inspiratory time may vary for every patient and may varyper breath for each patient. Double triggering may also result whenthere is mismatch between flow and set inspiratory time and patientdesired flow and neurological inspiratory time.

According to embodiments, double triggering may occur as a result ofvarious patient conditions and/or inappropriate ventilator settings.Thus, according to embodiments, double triggering detection module 224may evaluate various ventilatory parameter data based on one or morepredetermined thresholds to detect the presence of double triggering.For example, double triggering detection module 224 may evaluateexpiratory time, exhaled tidal volume, inspiratory time setting (T_(I)),patient circuit connection, etc. and compare the evaluated parameters toone or more predetermined thresholds. In order to prevent unnecessaryalarms, prompts, notifications, and/or recommendations, thresholds andconditions are utilized by the double triggering detection module 224 todetermine when double triggering has occurred with sufficient frequencyto warrant notification of the operator. For example, in someembodiments, a double trigger that occurs in isolation from any otherdouble trigger will not be considered enough to warrant an occurrence ofdouble triggering by the double triggering detection module 224. As usedherein any threshold, condition, setting, parameter, or frequency thatis “predetermined” may be input or selected by the operator and/or maybe set or selected by the ventilator.

In embodiments, the double triggering detection module 224 may detectdouble triggering when one or more predetermined thresholds are breachedat a predetermined frequency. In some embodiments, the double triggeringdetection module 224 may detect double triggering when one or morepredetermined thresholds are breached at least three times within apredetermined amount of time. In alternative embodiments, the doubletriggering detection module 224 may detect double triggering when one ormore predetermined thresholds are breached by more than 30% of thepatient-initiated mandatory breaths within a predetermined amount oftime. In some embodiments, the double triggering detection module 224may detect double triggering when one or more predetermined thresholdsare breached more than 10% of the patient-initiated mandatory breathswithin a predetermined amount of time. The predetermined amount of timemay be any suitable range of time for determining if double triggeringhas occurred, such as any time ranging from 30 seconds to 240 seconds.

According to some embodiments, double triggering detection module 224may detect double triggering when a double trigger has occurred at leastthree times within the last 60 seconds. According to furtherembodiments, double triggering detection module 224 may detect doubletriggering when more than 30% of the patient-initiated mandatory breathshave a doable trigger within the last 180 seconds. According toadditional embodiments, double triggering defection module 224 maydetect double triggering when more than 10% of the patient-initiatedmandatory breaths have a double trigger within the last 60 seconds. Thedouble triggering detection module 224 may begin the evaluation at thebeginning of each patient-initiated breath.

In some embodiments, double triggering detection module 224 detects adouble trigger when one or more of the following conditions are met:

-   -   1. expiratory time for a patient-initiated mandatory breath is        less than 240 milliseconds (ms);    -   2. the exhaled tidal volume associated with the expiratory        period is less than 10% of the delivered tidal volume of the        prior inspiratory period; and    -   3. no disconnect alarm is detected.        In further embodiments, condition number 1, listed above, may        refer to any suitable expiratory time threshold. For example, in        an alternative embodiment the expiratory time threshold is an        expiratory time of less than 230 ms, 220 ms, 210 ms, 200 ms, or        190 ms depending upon the type of ventilator, patient, breath        type, ventilator parameters, ventilator settings, and/or        ventilator modes, etc. Condition number 3 listed above, is        considered a “threshold” in the present disclosure and in the        listed claims. Further, the detection of any yes/no “condition”        is considered a “threshold” in the present disclosure and in the        listed claims. In an embodiment of the double triggering        detection system, all three of the above conditions must be        present for the double triggering detection module 224 to detect        a double trigger.

The three thresholds listed above are just one example list of possibleconditions that could be used to indicate double triggering. Anysuitable list of conditions for determining the occurrence of doubletriggering may be utilized. For example, other suitableconditions/thresholds that may be utilized to determine that doubletriggering is implicated include a determination that the patientcircuit has not become disconnected, an analysis of pressure duringexhalation, a comparison of the estimated patient's neural inspiratorytime to inspiratory time delivered by the ventilator, an analysis of endtidal carbon dioxide (ETCO₂), an analysis of volumetric carbon dioxide(VCO₂), a determination that the expired volume is less than 50% of thedelivered volume, a determination that monitored PEEP is a negativenumber for one second or less during the inspiratory effort, and ananalysis of a ratio of inspiratory to expiratory time (I:E ratio).

Ventilator 202 may further include a smart prompt module 226. As may beappreciated, multiple ventilatory parameters may be monitored andevaluated in order to detect an implication of double triggering. Inaddition, when double triggering is implicated, many clinicians may notbe aware of adjustments to ventilatory parameters that may reduce oreliminate double triggering. As such, upon detection of doubletriggering, the smart prompt module 226 may be configured to notify theclinician that double triggering is implicated and/or to providerecommendations to the clinician for mitigating double triggering. Forexample, smart prompt module 226 may be configured to notify theclinician by displaying a smart prompt on display monitor 204 and/orwithin a window of the GUI. According to additional embodiments, thesmart prompt may be communicated to and/or displayed on a remotemonitoring system communicatively coupled to ventilatory system 200.Alternatively, in an automated embodiment, the smart prompt module 226may communicate with a ventilator control system so that therecommendation may be automatically implemented to mitigate doubletriggering.

In order to accomplish the various aspects of the notification and/orrecommendation message display, the smart prompt module 226 maycommunicate with various other components and/or modules. For instance,smart prompt module 226 may be in communication with data processingmodule 222, double triggering detection module 224, or any othersuitable module or component of the ventilatory system 200. That is,smart prompt module 226 may receive an indication that double triggeringhas been implicated by any suitable means. In addition, smart promptmodule 226 may receive information regarding one or more parameters thatimplicated the presence of double triggering and information regardingthe patient's ventilatory settings and treatment. Further, according tosome embodiments, the smart prompt module 226 may have access to apatient's diagnostic information (e.g., regarding whether the patienthas ARDS, COPD, asthma, emphysema, or any other disease, disorder, orcondition).

Smart prompt module 226 may further comprise additional modules formaking notifications and/or recommendations to a clinician regarding thepresence of double triggering. For example, according to embodiments,smart prompt module 226 may include a notification module 228 and arecommendation module 230. For instance, smart prompts may be providedaccording to a hierarchical structure such that a notification messageand/or a recommendation message may be initially presented in summarizedform and, upon clinician selection, an additional detailed notificationand/or recommendation message may be displayed. According to alternativeembodiments, a notification message may be initially presented and, uponclinician selection, a recommendation message may be displayed.Alternatively or additionally, the notification message may besimultaneously displayed with the recommendation message in any suitableformat or configuration.

Specifically, according to embodiments, the notification message mayalert the clinician as to the detection of a patient condition, a changein patient condition, or an effectiveness of ventilatory treatment. Forexample, the notification message may alert the clinician that doubletriggering has been detected. The notification message may further alertthe clinician regarding the particular ventilatory parameter(s) thatimplicated double triggering (e.g., T_(E)<210 ms, etc.)

Additionally, according to embodiments, the recommendation message mayprovide various suggestions to the clinician for addressing a detectedcondition. That is, if double triggering has been detected, therecommendation message may suggest that the clinician consider changingto a spontaneous breath type, such as PA, PS, or VS etc. According toadditional embodiments, the recommendation message may be based on theparticular ventilatory parameter(s) that implicated double triggering.Additionally or alternatively, the recommendation message may be basedon current ventilatory settings (e.g., breath type) such thatsuggestions are directed to a particular patient's treatment.Additionally or alternatively, the recommendation message may be basedon a diagnosis and/or other patient attributes. Further still, therecommendation message may include a primary recommendation message anda secondary recommendation message.

As described above, smart prompt module 226 may also be configured withnotification module 228 and recommendation module 230. The notificationmodule 228 may be in communication with data processing module 222,double triggering detection module 224, or any other suitable module toreceive an indication that double triggering has been detected.Notification module 228 may be responsible for generating a notificationmessage via any suitable means. For example, the notification messagemay be provided as a tab, banner, dialog box, or other similar type ofdisplay. Further, the notification messages may be provided along aborder of the graphical user interface, near an alarm display or bar, orin any other suitable location. A shape and size of the notificationmessage may further be optimized for easy viewing with minimalinterference to other ventilatory displays. The notification message maybe further configured with a combination of icons and text such that theclinician may readily identify the message as a notification message.

The recommendation module 230 may be responsible for generating one ormore recommendation messages via any suitable means. The one or morerecommendation messages may provide suggestions and informationregarding addressing a detected condition and may be accessible from thenotification message. For example, the one or more recommendationmessages may identify the parameters that implicated the detectedcondition, may provide suggestions for adjusting one or more ventilatoryparameters to address the detected condition, may provide suggestionsfor checking ventilatory equipment or patient position, or may provideother helpful information. Specifically, the one or more recommendationmessages may provide suggestions and information regarding doubletriggering.

According to embodiments, based on the particular parameters thatimplicated double triggering, the recommendation module 230 may providesuggestions for addressing double triggering. That is, if doubletriggering is implicated, the one or more recommendation messages mayinclude suggestions for the following:

-   -   increasing T_(I) by changing the flow pattern, setting to        decelerating ramp;    -   changing the flow pattern setting to decelerating ramp;    -   increasing set T_(I);    -   decreasing set E_(SENS);    -   decreasing peak flow;    -   increasing set V_(T);    -   changing modes or breath types;    -   increasing set V_(T) while increasing peak flow rate setting to        maintain T_(I);    -   increasing peak flow rate setting to maintain T_(I);    -   increasing set V_(T) and changing the flow pattern to square;    -   changing flow pattern to square; and    -   etc.

Additionally or alternatively, the one or more recommendation messagesmay be based on a patient's diagnosis or other clinical data. Accordingto some embodiments, if a patient has been diagnosed with COPD, theventilator may be configured with adjusted thresholds. In furtherembodiments, if a patient has been diagnosed with emphysema, theventilator may be configured with adjusted thresholds accordingly.

According to still other embodiments, the recommendation message mayinclude a primary message and a secondary message. That is, a primarymessage may provide suggestions that are specifically targeted to thedetected condition based on the particular parameters that implicatedthe condition. Alternatively, the primary message may providesuggestions that may provide a higher likelihood of mitigating thedetected condition. The secondary message may provide more generalsuggestions and/or information that may aid the clinician in furtheraddressing and/or mitigating the detected condition. For example, theprimary message may provide a specific suggestion tor adjusting aparticular parameter to mitigate the detected condition (e.g., considerdecreasing set E_(SENS)). Alternatively, the secondary message mayprovide general suggestions for addressing the detected condition.

Additionally or alternatively, the one or more recommendation messagesmay also be based on current ventilator settings for the patient. Forexample, if double triggering was implicated during a VC breath type,where the patient's current ventilator settings included a setT_(I)<IBW-predicted T_(I), flow pattern set to square, and set V_(T)≧8ml/kg, then the one or more recommendation messages may suggestincreasing the time for inspiration by changing the flow pattern settingto a decelerating ramp or decreasing the peak flow rate. Further in thisexample, a secondary recommendation message may suggest changing thebreath type to VC+, PC, or a spontaneous breath type, such as PA, PS, orVS. Table 1 below lists various example primary and secondaryrecommendations for volume-control ventilation based on the listedcurrent ventilator settings.

TABLE 1 VC ventilation recommendation messages based on currentventilator settings. Ventilator Settings Primary Recommendation MessageSecondary Recommendation Message Set (calculated) T_(I) is < Considerincreasing the time Consider changing to VC+, IBW-predicted T_(I); forinspiration by changing PC or a spontaneous breath Flow pattern is setto the flow pattern setting to type such as PA, PS, VS. square; anddecelerating ramp, Set V_(T) < 8 ml/kg. decreasing peak flow rate, orincreasing set V_(T). Set (calculated) T_(I) is < Consider increasingthe time Consider changing to VC+, IBW-predicted T_(I); for inspirationby decreasing PC or a spontaneous breath Flow pattern is set to the peakflow rate setting. type such as PA, PS, or VS. decelerating ramp; andV_(T) ≧ 8 ml/kg. Set (calculated) T_(I) is < Consider increasing thetime Consider changing to VC+, IBW-predicted T_(I); for inspiration bydecreasing PC or a spontaneous breath Flow pattern is set to the peakflow rate setting or type such as PA, PS, VS. decelerating ramp; andincreasing set V_(T). V_(T) < 8 ml/kg. Set (calculated) T_(I) is ≧Consider increasing set V_(T) Consider changing to VC+, IBW-predictedT_(I); and while increasing the peak PC or a spontaneous breath Flowpattern is set to flow rate setting to maintain type such as PA, PS, orVS. square. T_(I). Set (calculated) T_(I) is ≧ Consider increasing setV_(T) Consider changing to VC+, IBW-predicted T_(I); and while changingthe flow PC or a spontaneous breath Flow pattern is set to patternsetting to square type such as PA, PS, or VS. decelerating ramp. and/orincreasing the peak flow rate setting to maintain T_(I).

In some embodiments, if double triggering is implicated during a PC orVC+ breath type, the one or more recommendation messages may suggestincreasing a set T_(I).

According to further embodiments, if double triggering is implicatedduring the PC or VC+ breath type, a secondary recommendation message maysuggest changing to a spontaneous breath type, such as PA, PS, or VSbreath type.

According to further embodiments, if double triggering is implicatedduring a PS or VS breath type, the one or more recommendation messagesmay suggest decreasing a set E_(sens). In some embodiments, if doubletriggering is implicated during the PS or VS breath type, a secondaryrecommendation message may suggest changing to a spontaneous breathtype, such as PA.

Smart prompt module 226 may also be configured such that notificationand/or recommendation messages may be displayed in a partiallytransparent window or format. The transparency may allow fornotification and/or recommendation messages to be displayed such thatnormal ventilator GUI and respiratory data may be visualized behind themessages. This feature may be particularly useful for displayingdetailed messages. As described previously, notification and/orrecommendation messages may be displayed in areas of the display screenthat are either blank or that cause minimal distraction from therespiratory data and other graphical, representations provided by theGUI. However, upon selective expansion of a message, respiratory dataand graphs may be at least partially obscured. As a result, translucentdisplay may provide the detailed message such that it is partiallytransparent. Thus, graphical and other data may be visible behind thedetailed alarm message.

Additionally, notification and/or recommendation messages may provideimmediate access to the display and/or settings screens associated withthe detected condition. For example, an associated parameter settingsscreen may be accessed from a notification and/or a recommendationmessage via a hyperlink such that the clinician may address the detectedcondition as necessary. An associated parameter display screen may alsobe accessed such that the clinician may view clinical data associatedwith the detected condition in the form of charts, graphs, or otherwise.That is, according to embodiments, the clinician may access theventilatory data that implicated the detected condition for verificationpurposes. For example, when double triggering has been implicated,depending on the particular ventilatory parameters that implicated thedouble triggering, the clinician may be able to access ventilatorysettings for addressing double triggering (e.g., a settings screen foradjusting V_(T), T_(I), etc.) and/or to view associated ventilatoryparameters that implicated double triggering (e.g., a graphics screendisplaying historical flow waveforms, volume waveforms, and/or pressurewaveforms that gave rise to implications of double triggering).

According to embodiments, upon viewing the notification and/orrecommendation messages, upon addressing the detected condition byadjusting one or more ventilatory settings or otherwise, or upon manualselection, the notification and/or recommendation messages may hecleared from the graphical user interface. According to someembodiments, smart prompt module 226 clears the one or more messagesfrom the graphical user interface if the breath type is changed. Infurther embodiments, smart prompt module 226 clears the one or moremessages from the graphical user interlace if a ventilator settingchange was performed by the operator and within a predetermined amountof time (e.g. 60 seconds or 180 seconds) two patient-initiated mandatorybreaths are greater than the predetermined expiratory time threshold(e.g. ≧210 ms) and/or none of the patient-initiated mandatory breathshave an expiratory time less than the predetermined expiratory timethreshold (e.g. <210 ms), in further embodiments, smart prompt module226 clears the one or more messages from the graphical user interface,if within a predetermined amount of time (e.g. 60 seconds or 180seconds) three patient-initiated mandatory breaths are greater than thepredetermined expiratory time threshold (e.g., ≧210 ms) and/or none ofthe patient-initiated mandatory breaths have an expiratory time lessthan the predetermined expiratory time threshold (e.g., <210 ms).

Double Triggering Detection during Ventilation of a Patient

FIG. 3 is a flow chart illustrating an embodiment of a method 300 fordetecting an implication of double triggering.

As should be appreciated, the particular steps and methods describedherein are not exclusive and, as will be understood by those skilled inthe art, the particular ordering of steps as described herein is notintended to limit the method, e.g., steps may be performed in differingorder, additional steps may be performed, and disclosed steps may beexcluded without departing from the spirit of the present methods.

The illustrated embodiment of the method 300 depicts a method fordetecting double triggering during ventilation of a patient. Method 300begins with an initiate ventilation operation 302. Initiate ventilationoperation 302 may further include various additional operations. Forexample, initiate ventilation operation 302 may include receiving one ormore ventilatory settings associated with ventilation of a patient(e.g., at receive settings operation 304). For example, the ventilatormay be configured to provide ventilation to a patient. As such, theventilatory settings and/or input received may include a prescribedV_(T), set flow (or peak flow), predicted or ideal body weight (PBW orIBW), etc. According to some embodiments, a predicted T_(E) may bedetermined based on normal respiratory and compliance values or valueranges based on the patient's PBW or IBW.

According to some embodiments, initiate ventilation operation 302 mayfurther include receiving diagnostic-information regarding the patient(e.g., at receive diagnosis operation 306, represented with dashed linesto identify the receive diagnosis operation 306 as optional). Forexample, according to embodiments, the clinician may indicate that thepatient has been diagnosed with ARDS, COPD, emphysema, asthma, etc. Theventilator may be further configured to associate a patient diagnosiswith various conditions (e.g., increased resistance associated withCOPD, increased likelihood of alveolar collapse associated with ARDS,etc.).

At deliver ventilation operation 308, the ventilator providesventilation to a patient, as described above. That is, according toembodiments, the ventilator provides ventilation based on the set breathtype. For example, during a VC breath type, the ventilator providesventilation based on a prescribed V_(T). In this example, the ventilatormay deliver gases to the patient at a set flow at a set RR. Whenprescribed V_(T) has been delivered, the ventilator may initiate theexpiratory phase.

While ventilation is being delivered, the ventilator may conduct variousdata processing operations. For example, at data processing operation310, the ventilator may collect and/or derive various ventilatoryparameter data associated with ventilation of the patient. For example,as described above, the ventilator may collect data regarding expiratorytime, V_(T), T_(I), etc. parameters. Additionally, the ventilator mayderive various ventilatory parameter data based on the collected data,e.g., IBW-predicted T_(I), volume, respiratory resistance, respiratorycompliance, etc. As described previously, measurements for respiratoryresistance and/or compliance may be trended continuously for a patientbecause ventilatory data may he obtained without sedating the patient orotherwise. Additionally, the ventilator may generate various graphicalrepresentations of the collected and/or derived ventilatory parameterdata, e.g., flow waveforms, pressure waveforms, pressure-volume loops,flow-volume loops, etc.

At analyze operation 312, the ventilator may evaluate collected and/orderived data to determine whether a certain patient condition exists.For example, according to embodiments, the ventilator may evaluate thevarious collected and derived parameter data, including expiratory time,delivered tidal volume, etc., based on one or more predeterminedthresholds. According to embodiments, the ventilator may furtherevaluate the ventilatory parameter data in light of the patient'sspecific parameter settings, including set tidal volume, etc., and/orthe patient's diagnostic information. In some embodiments, theevaluation of the various collected and derived parameter data includesa patient circuit disconnection operation. The patient circuitdisconnection operation determines whether the patient circuit hasbecome disconnected from the patient and/or ventilator. The analyzeoperation 312 determines that a patient circuit is disconnected by anysuitable means. In some embodiments, the analyze operation 312determines that the patient circuit has become disconnected byevaluating exhaled pressure and/or exhaled volume. In furtherembodiments, analyze operation 312 determines if the patient circuit isdisconnected by determining if a disconnect alarm has been executed. Ifthe disconnect alarm has been executed, then analyze operation 312determines that the patient circuit is disconnected. If the disconnectalarm has not been executed, then analyze operation 312 determines thatthe patient circuit is connected.

According to some embodiments, at detect double triggering operation 314the ventilator may determine whether double triggering is implicated byevaluating expiratory time, exhaled tidal volume, inspiratory timesetting (T_(I)), patient circuit connection, etc., and compare theevaluated parameters to one or more predetermined thresholds. In orderto prevent unnecessary alarms, notifications, and/or recommendations,thresholds and conditions are utilized by the detect double triggeringoperation 314 to determine when double triggering has occurred withsufficient frequency to warrant notification of the operator. Forexample, in some embodiments, a double trigger that occurs in isolationfrom any other double trigger will not be considered enough to warrantan occurrence of double triggering by detect double triggering operation314.

In some embodiments, at detect double triggering operation 314 theventilator may determine whether double triggering is implicated basedon a predetermined frequency. In further embodiments, at detect doubletriggering operation 314 the ventilator may determine whether doubletriggering is implicated based on whether a double trigger occurred morethan three times, for more than 30% of the patient-initiated mandatorybreaths, or for more than 10% of the patient-initiated mandatory breathswithin a predetermined amount of time (e.g. 60 seconds or 180 seconds)at analyze operation 312. For example, a double trigger is detected whenat least one of the following three predetermined thresholds areexceeded:

-   -   1. expiratory time for a patient-initiated mandatory breath is        less than 240 ms;    -   2. exhaled tidal volume associated with the expiratory period is        less than 10% of the delivered tidal volume of the prior        inspiratory period; and    -   3. a disconnect alarm is not detected.

In further embodiments, threshold number 1, listed above, may be anysuitable period. For example, in an alternative embodiment theexpiratory time threshold is an expiratory time of less than 230 ms, 220ms, 210 ms, 200 ms, or 190 ms depending upon the type of ventilator,patient, breath type, ventilator parameters, ventilator settings, and/orventilator modes, etc. In some embodiment, the predetermined amount oftime starts at the beginning of each patient-initiated breath. If doubletriggering is implicated, the detect double triggering operation 314 mayproceed to issue smart prompt operation 316. If double triggering is notimplicated, the detect double triggering operation 314 may return toanalyze operation 312.

The three thresholds listed above are just one example list of possibleconditions that could be used to indicate double triggering in thedetect double triggering operation 314. Any suitable list of conditionfor determining the occurrence of double triggering may be utilized bythe detect double triggering operation 314. As may be appreciated, theventilator may determine whether double triggering is implicated atdetect double triggering operation 314 via any suitable means. Indeed,any of the above described ventilatory parameters may be evaluatedaccording to various thresholds for detecting double triggering.Further, the disclosure regarding specific ventilatory parameters asthey may implicate double triggering is not intended to be limiting. Infact, any suitable ventilatory parameter may be monitored and evaluatedfor detecting double triggering within the spirit of the presentdisclosure. As such, if double triggering is implicated via any suitablemeans, the detect double triggering operation 314 may proceed to issuesmart prompt operation 316. If double triggering is not implicated, thedetect double triggering operation 314 may return to analyze operation312.

At issue smart prompt operation 316, the ventilator may alert theclinician via any suitable means that double triggering has beenimplicated. For example, according to embodiments, the ventilator maydisplay a smart prompt including a notification message and/or arecommendation message regarding the detection of double triggering onthe GUI. According to alternative embodiments, the ventilator maycommunicate the smart prompt, including the notification message and/orthe recommendation message, to a remote monitoring systemcommunicatively coupled to the ventilator.

According to embodiments, the notification message may alert theclinician that double triggering has been detected and, optionally, mayprovide information regarding the ventilatory parameter(s) thatimplicated double triggering. According to additional embodiments, therecommendation message may provide one or more suggestions formitigating double triggering. According to further embodiments, the oneor more suggestions may be based on the patient's particular ventilatorysettings (e.g. breath type, T_(I), V_(T), etc.) and/or diagnosis.According to some embodiments, the clinician may access one or moreparameter setting and/or display screens from the smart prompt via ahyperlink or otherwise for addressing doable triggering. According toadditional or alternative embodiments, a clinician may remotely accessone or more parameter and/or display screens from the smart prompt via ahyperlink or otherwise for remotely addressing double triggering.

Smart Prompt Generation regarding Double Triggering Detection

FIG. 4 is a flow chart illustrating an embodiment of a method 400 forissuing a smart prompt upon detecting an implication of doubletriggering.

As should be appreciated, the particular steps and methods describedherein are not exclusive and, as will be understood by those skilled inthe art, the particular ordering of steps as described herein is notintended to limit the method, e.g., steps may be performed in differingorder, additional steps may be performed, and disclosed steps may beexcluded without departing from the spirit of the present methods.

The illustrated embodiment of the method 400 depicts a method forissuing a smart prompt upon detecting double triggering duringventilation of a patient. Method 400 begins with detect operation 402,wherein the ventilator defects that double triggering is implicated, asdescribed above in method 300.

At identify ventilatory parameters operation 404, the ventilator mayidentify one or more ventilatory parameters that implicated doubletriggering. In order to prevent unnecessary alarms, notifications,and/or recommendations, thresholds and conditions are utilized byidentify ventilatory parameters operation 404 to determine when doubletriggering has occurred with sufficient infrequency to warrantnotification of the operator. For example, in some embodiments, a doubletrigger that occurs in isolation from any other double trigger will notbe considered enough to warrant an occurrence of double triggering byidentify ventilatory parameters operation 404.

For example, the ventilator may recognize that double triggering wasimplicated based on whether a double trigger occurred, more than threetimes for more than 30% of the patient-initiated mandatory breaths, orfor more than 10% of the patient-initiated mandatory breaths within apredetermined amount of time (e.g. 60 seconds or 180 seconds). Forexample, a double trigger happens when at least one of three followingpredetermined thresholds are exceeded:

-   -   1. expiratory time for a patient-initiated mandatory breath is        less than 240 ms;    -   2. exhaled tidal volume associated with the expiratory period is        less than 10% of the delivered tidal volume of the prior        inspiratory period; and    -   3. a disconnect alarm is not detected.

In further embodiments, threshold number 1, listed above, may refer toany suitable expiratory period. For example, in an alternativeembodiment the expiratory time threshold is an expiratory time of lessthan 230 ms, 220 ms, 210 ms, 200 ms, or 190 ms depending upon the typeof ventilator, patient, breath type, ventilator parameters, ventilatorsetting, and/or ventilator modes, etc. In some embodiment, thepredetermined amount of time starts at the beginning of eachpatient-initiated breath. The three thresholds listed above are just oneexample list of possible conditions that could be used to indicatedouble triggering in the parameters operation 404. Any suitable list ofconditions for determining the occurrence of double triggering may beutilized by the parameters operation 404. As may be appreciated, theventilator may use information regarding ventilatory parameters thatimplicated double triggering in determining an appropriate notificationand/or recommendation message of the smart prompt.

At identify settings operation 406, the ventilator may identify one ormore current ventilatory settings associated with the ventilatorytreatment of the patient. For example, current ventilatory settings mayhave been received upon initiating ventilation for the patient and mayhave been determined by the clinician or otherwise (e.g., breath type,oxygenation, PBW or IBW, disease conditions, etc.). For instance,current ventilatory settings associated with ventilation for a patientmay include, V_(T), T_(I), flow, E_(SENS), flow pattern, IBW-predictedbased on T_(I) etc. In addition, a predicted T_(E) may have beendetermined based on normal respiratory resistance and compliance valuesand the patient's PBW (or IBW). As may be appreciated, the ventilatormay use information regarding current ventilatory settings indetermining an appropriate notification and/or recommendation message ofthe smart prompt.

At identify patient diagnosis operation 408, the ventilator mayoptionally identify patient diagnosis information received from aclinician (represented with dashed lines to identity the operation asoptional). For example, according to embodiments, the clinician mayindicate during ventilation initiation or otherwise that the patient wasdiagnosed with COPD, ARDS, emphysema, asthma, etc. As may beappreciated, the ventilator may use information regarding a patient'sdiagnosis in determining an appropriate notification and/orrecommendation message of the smart prompt.

At determine operation 410, the ventilator may determine an appropriatenotification message. For example, the appropriate notification messagemay alert the clinician that double triggering has been implicated and,optionally, may provide information regarding the ventilatoryparameter(s) that implicated double triggering. For example, theappropriate notification may alert the clinician that double triggeringwas implicated because a double trigger occurred in more than 10% of thepatient-initiated mandatory breaths, more than 30% of thepatient-initiated mandatory breaths, more than three instances of thepatient-initiated mandatory breaths, more than 8 instances of thepatient-initiated mandatory breaths, etc. within the predeterminedamount of time. In some embodiments, the predetermined amount of time ismeasured from the beginning of each patient-initiated breath. Forexample, if double triggering was detected because a double trigger wasdetected in 3 or more instances of the patient-initiated mandatorybreaths within the last 60 seconds, the ventilator may offer one or morenotification messages that may include: “Double triggering has occurredin more than 3 instances of the breaths in one minute.” In alternativeembodiments, measured parameters such as inspiratory time and volume maybe utilized as the notification message.

At determine operation 412, the ventilator may determine an appropriateprimary recommendation message. The appropriate primary recommendationmessage may provide one or more specific suggestions for mitigatingdouble triggering. According to some embodiments, in determining theappropriate primary recommendation message, the ventilator may take intoconsideration the one or more monitored ventilatory parameters thatimplicated double triggering.

According to other embodiments, in determining an appropriate primaryrecommendation message the ventilator may take into consideration one ormore of the patient's ventilatory settings. For example, if the breathtype is volume-control (VC) and if T_(I) is greater than anIBW-predicted T_(I), and the flow pattern is set to decelerating ramp,the ventilator may offer one or more recommendation messages that mayinclude: “Consider increasing set V_(T) while changing flow patternsetting to square”; “Consider increasing peak flow rate setting tomaintain T_(I).” In another example, if the breath type is set topressure-control, then the ventilator may offer one or morerecommendation messages that may include: “Consider increasing the setT_(I).” Any of the primary recommendations as discussed above for anybreath type may be utilized by method 400.

According to further embodiments, in determining the appropriate primaryrecommendation message the ventilator may take into consideration thepatient's diagnosis. For example, if a patient has been diagnosed withCOPD or ARDS, in determining an appropriate primary recommendationmessage, the ventilator may consider the patient's diagnosis.

At determine operation 414, the ventilator may determine an appropriatesecondary recommendation message. The secondary recommendation messagemay provide one or more general suggestions for mitigating doubletriggering. For example, the secondary recommendation message mayinclude: “Consider changing to VC+ or PC; Consider changing tospontaneous breath type such as PA, PS, or VS; Consider changing to aspontaneous breath type such as PA.” The secondary recommendationmessage may provide additional recommendations for mitigating doubletriggering. In further embodiments, the appropriate secondaryrecommendation message may take into consideration the patient's currentventilatory settings. That is, during a PS or a VS breath type, theventilator may suggest changing to a spontaneous breath type such as PAin the secondary recommendation message.

At issue smart prompt operation 416, the ventilator may alert theclinician via any suitable means that double triggering has beenimplicated. For example, according to embodiments, a smart prompt mayinclude an appropriate notification message and an appropriaterecommendation message regarding the presence of double triggering.Additionally or alternatively, the smart prompt may include anappropriate notification message, an appropriate primary recommendationmessage, and an appropriate secondary recommendation message. The smartprompt may be displayed via any suitable means, e.g., on the ventilatorGUI and/or at a remote monitoring station, such that the clinician isalerted as to the potential presence of double triggering and offeredadditional information and/or recommendations for mitigating the doubletriggering, as described herein.

In some embodiments, a ventilatory system for issuing a smart promptwhen double triggering is implicated during ventilation of a patient isdisclosed. The ventilatory system includes: means for collecting dataassociated with ventilatory parameters; means for processing thecollected ventilatory parameter data, wherein the means for processingthe collected ventilatory parameter data includes means for derivingventilatory parameter data from the collected ventilatory parameterdata; means for analyzing the processed ventilatory parameter data,wherein the means for analyzing the processed ventilatory parameter dataincludes: means for receiving at least one predetermined thresholdassociated with the processed ventilatory parameter data; and means fordetecting whether the processed ventilatory parameter data breaches thereceived at least one predetermined threshold at a predeterminedfrequency; means for determining that double triggering is implicatedfor a patient upon detecting that the processed ventilatory databreaches the received at least one predetermined threshold at thepredetermined frequency; and means for issuing a smart prompt when thedouble triggering is implicated. In further embodiments, the means forthe medical ventilator are illustrated in FIGS. 1 and 2 and aredescribed in the above descriptions of FIGS. 1 and 2. However, the meansdescribed above for FIGS. 1 and 2 and illustrated in FIGS. 1 and 2 arebut one example only and are not meant to be limiting.

Ventilator GUI Display of Initial Smart Prompt

FIG. 5 is an illustration of an embodiment of a graphical user interface500 displaying a smart prompt having a notification message 512.

Graphical user interface 500 may display various monitored and/orderived data to the clinician during ventilation of a patient. Inaddition, graphical user interface 500 may display various messages tothe clinician (e.g., alarm messages, etc.). Specifically, graphical userinterlace 500 may display a smart prompt as described herein.

According to embodiments, the ventilator may monitor and evaluatevarious ventilatory parameters based on one or more predeterminedthresholds to detect double triggering. As illustrated, a flow waveformmay be generated and displayed by the ventilator on graphical userinterlace 500. As further illustrated, the flow waveform may bedisplayed such that inspiratory flow 502 is represented in a differentcolor (e.g., green) than explanatory flow 504 (e.g., yellow).Additionally, as illustrated, a double trigger 506 occurs when theventilator delivers two or more breaths separated by a very shortexpiratory time, with at least one breath being triggered by thepatient. Double triggering results when there is a mismatch between theventilation setting for inspiratory time and the patient's neurologicalinspiratory time. Double triggering may also result when there is amismatch between the flow and set inspiratory time and the patient'sdesired flow and neurological inspiratory time. In order to preventunnecessary alarms, notifications, and/or recommendations, thresholdsand conditions are utilized to determine when double triggering hasoccurred with sufficient frequency to warrant notification of theoperator.

That is, double triggering may be detected if a double trigger occurredmore than three times, for more than 30% of the patient-initiatedmandatory breaths, or for more than 10% of the patient-initiatedmandatory breaths within a predetermined amount of time (e.g. 60 secondsor 180 seconds). For example, a double trigger happens when at least oneof three following predetermined thresholds are breached:

-   -   1. expiratory time for a patient-initiated mandatory breath is        less than 240 ms;    -   2. exhaled tidal volume associated with the expiratory period is        less than 10% of the delivered tidal volume of the prior        inspiratory period; and    -   3. a disconnect alarm is not detected.

In further embodiments, threshold number 1, listed above, may be anysuitable period. For example, in an alternative embodiment theexpiratory time threshold is an expiratory time of less than 230 ms, 220ms, 210 ms, 200 ms, or 190 ms depending upon the type of ventilator,patient, breath type, ventilator parameters, ventilator setting, and/orventilator modes, etc. In some embodiment, the predetermined amount oftime starts at the beginning of each patient-initiated breath. The threethresholds listed above are just one example list of possible conditionsthat could be used to indicate doable triggering. Any suitable list ofconditions for determining the occurrence of double triggering may beutilized.

Upon a determination that double triggering is implicated, the graphicaluser interlace 500 may display a smart prompt, e.g., smart prompt 510.

According to embodiments, smart prompt 510 may be displayed in anysuitable location such that a clinician may be alerted regarding adetected patient condition, but while allowing other ventilatorydisplays and data to be visualized substantially simultaneously. Asillustrated, smart prompt 510 is presented as a bar or banner across anupper region of the graphical user interlace 500. However, as previouslynoted, smart prompt 510 may be displayed as a tab, icon, button, banner,bar, or any other suitable shape or form. Further, smart prompt 510 maybe displayed in any suitable location within the graphical userinterface 500. For example, smart prompt 510 may be located along anyborder region of the graphical user interface 500 (e.g., top, bottom, orside borders) (not shown), across an upper region (shown), or in anyother suitable location. Further, as described herein, smart prompt 510may he partially transparent (not shown) such that ventilatory displaysand data may be at feast partially visible behind smart prompt 510.

Specifically, smart prompt 510 may alert the clinician that doubletriggering has been defected, for example by notification message 512.As described herein, notification message 512 may alert the clinicianthat double triggering is implicated via any suitable means, e.g.,“Double Triggering Alert” (shown), “Double Triggering Detected” (notshown), or “Double Triggering Implicated” (not shown). Smart prompt 510may further include information regarding ventilatory parameters thatimplicated double triggering. For example, if double triggering wasdetected based on two set mechanical breaths being delivered for onepatient-initiated mandatory breath three times in one minute, thisinformation may be displayed by the notification message 512 (e.g.,“Double Triggering has occurred in more than 10% of the breaths in aminute,” shown). According to the illustrated embodiment, parameterinformation 514 is provided along with the notification message 312 in abanner. According to alternative embodiments, in addition to thenotification message 512 and the parameter information 514, one or morerecommendation messages may be provided in an initial smart promptbanner (not shown). According to other embodiments, rather thanproviding information regarding ventilatory parameters that implicateddouble triggering in the initial smart prompt, this information may beprovided within an expanded portion (not shown) of smart prompt 510.

According to embodiments, smart prompt 510 may be expanded to provideadditional information and/or recommendations to the clinician regardinga detected patient condition. For example, an expand icon 516 may beprovided within a suitable area of the smart prompt 510. According toembodiments, upon selection of the expand icon 516 via any suitablemeans, the clinician may optionally expand the smart prompt 510 toacquire additional information and/or recommendations for mitigating thedetected patient condition. According to further embodiments, smartprompt 510 may include links (not shown) to additional settings and/ordisplay screens of the graphical user interface 500 such that theclinician may easily and quickly mitigate and/or verify the detectedcondition.

As may be appreciated, the disclosed data, graphics, and smart promptillustrated in graphical user interface 500 may be arranged in anysuitable order or configuration such that information and alerts may becommunicated to the clinician in an efficient and orderly manner. Thedisclosed data, graphics, and smart prompt are not to be understood asan exclusive array, as any number of similar suitable elements may bedisplayed for the clinician within the spirit of the present disclosure.Further, the disclosed data, graphics, and smart prompt are not to beunderstood as a necessary array, as any number of the disclosed elementsmay be appropriately replaced by other suitable elements withoutdeparting from the spirit of the present disclosure. The illustratedembodiment of the graphical user interface 500 is provided as an exampleonly, including potentially useful information and alerts that may beprovided to the clinician to facilitate communication of detected doubletriggering in an orderly and informative way, as described herein.

Ventilator GUI Display of Expanded Smart Prompt

FIG. 6 is an illustration of an embodiment of a graphical user interlace600 displaying an expanded smart prompt 606 having a notificationmessage and one or more recommendation messages 608.

Graphical user interface 600 may display various monitored and/orderived data to the clinician during ventilation of a patient. Inaddition, graphical user interface 600 may display an expanded smartprompt 606 including one or more recommendation messages 608 asdescribed herein.

According to embodiments, as described above, an expand icon 604 may beprovided within a suitable area of smart prompt 602. Upon selection ofthe expand icon 604, the clinician may optionally expand smart prompt602 to acquire additional information and/or recommendations formitigating the detected patient condition. For example, expanded smartprompt 606 may be provided upon selection of expand icon 604. Asdescribed above for smart prompt 510, expanded smart prompt 606 may bedisplayed as a tab, icon, button, banner, bar, or any other suitableshape or form. Further, expanded smart prompt 606 may be displayed inany suitable location within the graphical user interface 600. Forexample, expanded smart prompt 606 may be displayed below (shown) smartprompt 602, to a side (not shown) of smart prompt 602, or otherwiselogically associated with smart prompt 602. According to otherembodiments, an initial smart prompt may be hidden (not shown) upondisplaying expanded smart prompt 606. Expanded small prompt 606 may alsobe partially transparent (not shown) such that ventilatory displays anddata may be at least partially visible behind expanded smart prompt 606.

According to embodiments, expanded smart prompt 606 may compriseadditional information (not shown) and/or one or more recommendationmessages 608 regarding detected double triggering. For example, the oneor more recommendation messages 608 may include a primary recommendationmessage and a secondary recommendation message. The primaryrecommendation message may provide one or more specific suggestions formitigating double triggering. For example, if double triggering wasimplicated during volume-control ventilation and if T_(I) is greaterthan a IBW-predicted T_(I) and the flow pattern is set to deceleratingramp, then the ventilator may offer one or more primary recommendationmessages 608 that may include: “Consider increasing set V_(T) whilechanging flow pattern setting to square; Consider changing to VC+ or PC;Consider changing to spontaneous breath type such as PA, PS, or VS;Consider increasing peak flow rate setting to maintain T_(I).” Thesecondary recommendation message may provide one or more generalsuggestions for mitigating doable triggering. For example, the secondaryrecommendation message may include: “Consider changing to VC+ or PC;Consider changing to spontaneous breath type such as PA, PS, or VS;Consider changing to a spontaneous breath type such as PA.”

According to embodiments, expanded smart prompt 606 may also include oneor more hyperlinks 610, which may provide immediate access to thedisplay and/or settings screens associated with detected doubletriggering. For example, associated parameter settings screens may beaccessed from expanded smart prompt 606 via hyperlinks 610 such that theclinician may address detected double triggering by adjusting one ormore parameter settings as necessary. Alternatively, associatedparameter display screens may be accessed such that the clinician mayview clinical data associated with double triggering in the form ofcharts, graphs, or otherwise. That is, according to embodiments, theclinician may access the ventilatory data that implicated doubletriggering for verification purposes. For example, when doubletriggering has been implicated, depending on the particular ventilatoryparameters that implicated double triggering, the clinician may be ableto access associated parameter settings screens for addressing doubletriggering (e.g., settings screens for adjusting V_(T), T_(I), breathtype, etc). Additionally or alternatively, the clinician may be able toaccess and/or view display screens associated with the ventilatoryparameters that implicated double triggering (e.g., a graphics screendisplaying historical flow waveforms, volume waveforms, and/or pressurewaveforms that gave rise to implications of double triggering).

As may be appreciated, the disclosed smart prompt and recommendationmessages 608 illustrated in graphical user interface 600 may be arrangedin any suitable order or configuration such that information and alertsmay be communicated to the clinician in an efficient and orderly manner.Indeed the illustrated embodiment of the graphical user interface 600 isprovided as an example only, including potentially useful informationand recommendations that may be provided to the clinician to facilitatecommunication of suggestions for mitigating detected double trigging inan orderly and informative way, as described herein.

Unless otherwise indicated, all numbers expressing measurements,dimensions, and so forth used in the specification and claims are to heunderstood as being modified in all instances by the term “about.”Accordingly, unless indicated to the contrary, the numerical parametersset forth in the following specification and attached claims areapproximations that may vary depending upon the desired propertiessought to be obtained by the present disclosure. Further, unlessotherwise stated, the term “about” shall expressly include “exactly,”consistent with the discussions regarding ranges and numerical data.Concentrations, amounts, and other numerical data may be expressed orpresented herein in a range format. It is to be understood that such arange format is used merely for convenience and brevity and thus shouldbe interpreted flexibly to include not only the numerical valuesexplicitly recited as the limits of the range, but also to include allthe individual numerical values or sub-ranges encompassed within thatrange as if each numerical value and sub-range is explicitly recited. Asan illustration, a numerical range of “about 4 percent to about 7percent” should be interpreted to include not only the explicitlyrecited values of about 4 percent to about 7 percent, but also includeindividual values and sub-ranges within the indicated range. Thus,included in this numerical range are individual values such as 4.5, 5.25and 6 and subranges such as from 4-5, from 5-7, and from 5.5-6.5, etc.This same principle applies to ranges reciting only one numerical value.Furthermore, such an interpretation should apply regardless of thebreadth of the range or the characteristics being described.

It will be clear that the systems and methods described herein are welladapted to attain the ends and advantages mentioned as well as thoseinherent therein. Those skilled in the art will recognize that themethods and systems within this specification may be implemented in manymanners and as such is not to be limited by the foregoing exemplifiedembodiments and examples. In other words, functional elements beingperformed by a single or multiple components, in various combinations ofhardware and software, and individual functions can be distributed amongsoftware applications at either the client or server level. In thisregard, any number of the features of the different embodimentsdescribed herein may be combined into one single embodiment andalternative embodiments having fewer than or more than all of thefeatures herein described are possible.

While various embodiments have been described for purposes of thisdisclosure, various changes and modifications may be made which are wellwithin the scope of the present disclosure. Numerous other changes maybe made which will readily suggest themselves to those skilled in theart and which are encompassed in the spirit of the disclosure and asdefined in the appended claims.

1. A ventilator-implemented method for detecting double triggeringduring ventilation of a patient, the method comprising: collecting dataassociated with ventilatory parameters; processing the collectedventilatory parameter data, wherein the step of processing the collectedventilatory parameter data comprises deriving ventilatory parameter datafrom the collected ventilatory parameter data; analyzing the processedventilatory parameter data, wherein the step of analyzing the processedventilatory parameter data comprises: receiving at least onepredetermined threshold associated with the processed ventilatoryparameter data; and detecting whether the processed ventilatoryparameter data breaches the received at least one predeterminedthreshold at a predetermined frequency; determining that doubletriggering is implicated upon detecting that the processed ventilatorydata breaches the received at least one predetermined threshold at thepredetermined frequency; and issuing a smart prompt when the doubletriggering is implicated.
 2. The method of claim 1, wherein theprocessed ventilatory parameter data comprises exhaled tidal volume, andwherein the step of analyzing of the exhaled tidal volume furthercomprises: receiving a predetermined threshold for the exhaled tidalvolume, the predetermined threshold comprising: an exhaled tidal volumethat is less than 10 percent of a delivered tidal volume; determiningthe delivered tidal volume; and determining that the exhaled tidalvolume is less than 10 percent of the delivered tidal volume.
 3. Themethod of claim 1, wherein the processed ventilatory parameter datacomprises an expiratory time (T_(E)) for a patient-initiated mandatorybreath.
 4. The method of claim 3, wherein the step of analyzing theexpiratory time (T_(E)) for the patient-initiated mandatory breathcomprises: receiving a predetermined threshold for the expiratory time(T_(E)) the predetermined threshold comprising: an expiratory time(T_(E)) threshold of less than 240 ms; determining an expiratory time(T_(E)) for the patient-initiated mandatory breath; and determining thatthe expiratory time (T_(E)) is less than 240 ms.
 5. The method of claim3, wherein the step of analyzing the expiratory time (T_(E)) for thepatient-initiated mandatory breath comprises: receiving a predeterminedthreshold for the expiratory time (T_(E)), the predetermined thresholdcomprising: an expiratory time (T_(E)) threshold of less than 210 ms;determining an expiratory time (T_(E)) for the patient-initiatedmandatory breath; and determining that the expiratory time (T_(E)) isless than 210 ms.
 6. The method of claim 3, wherein the step ofanalyzing the expiratory time (T_(E)) for the patient-initiatedmandatory breath comprises: receiving a predetermined threshold for theexpiratory time (T_(E)) the predetermined threshold comprising: anexpiratory time (T_(E)) threshold of less than 190 ms; determining anexpiratory time (T_(E)) for the patient-initiated mandatory breath; anddetermining that the expiratory time (T_(E)) is less than 190 ms.
 7. Themethod of claim 1, wherein the processed ventilatory parameter datacomprises a disconnect alarm, and wherein the step of analyzing of thedisconnect alarm comprises: determining that the disconnect alarm hasnot been activated.
 8. The method of claim 1, further comprising:identifying one or more ventilatory settings associated with aventilatory treatment of the patient; determining an appropriate smartprompt based at least in part on evaluating the one or more ventilatorysettings; and wherein the issued smart prompt is the appropriate smartprompt.
 9. The method of claim 8, wherein the one or more ventilatorysettings are a ventilation breath type selected from a group ofventilation breath types of pressure controlled (PC),volume-targeted-pressure-control (VC+), pressure-support (PS), andvolume-support (VS). 10-22. (canceled)